Mike Slinn

Trust, Winning and Losing as an Expert Witness

Published 2021-01-08.
Time to read: 8 minutes.

Mike Slinn has been working in the tech industry for more than four decades. His passion for technology, coupled with his keen interest in unraveling puzzles, have allowed Mr. Slinn to excel as an expert witness in technology legal disputes. To date, he has been retained 19 times for his expert opinion.

Contact Mike Slinn to discuss how he might provide value.

This article is from the series entitled Technology Expert Articles for Attorneys. You might find the articles of interest if you are looking for a software expert witness, a technology expert witness, or a computer expert witness.

I have never been disqualified.
All my opinions have been accepted.

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This article is written for matters that require an expert opinion based on examination of evidence, followed by analysis. All of my opinions have been completely accepted in every case that I have acted as a software expert to date.

I am a professional software technologist and entrepreneur. Sometimes I work as an expert witness. Attorneys do not buy the opinion they desire from me, they merely purchase my time. My only job is to respond to questions that they ask of me. Sometimes I write software to process evidence so that I can learn the information necessary to answer the questions.

Most questions are of a purely technical nature, but sometimes they pertain to technical marketing. Issues often relate to trade secrets and intellectual property. My responses follow from facts, or stated premises where facts are unavailable.

How Do Experts Win?

As a software expert, I strive to win, but my definition of winning might surprise you: for a non-partisan expert witness, “winning” can only mean that their opinions were accepted.

Independent experts must not have an investment in the legal outcome of a case; conversely, they should not fear any personal impact from performing their duties in a professional and conscientious manner, regardless of the outcome of the case. Experts can “win” even in cases where their client has an unfavorable judgment.

How Do Experts Lose?

Experts can lose 3 ways:

  1. By being disqualified as an expert.
  2. By impeaching themselves.
  3. By having their opinions partially or completely dismissed.

Financial pressure is a common way for clients to attempt to influence an expert’s opinion. If payment is not made in advance, then an expert might be tempted to please their client so full payment is made promptly. This type of financial arrangement sets up a conflict of interest for the expert.

During discovery, I am often asked by the opposing counsel what my financial arrangements with my client are. If an expert agrees to payment terms that puts them into a conflict of interest, opposing counsel may be motivated to attempt to disqualify the expert.

Lawyers are Partisan Advocates

In most of the world, lawyers play by different rules than experts. The French words for male / female ‘attorney’ are ‘avocat’ and ‘avocate’. While lawyers must advocate for their clients, in most of the world experts must not.

US Expert Witnesses Are Allowed To Be Partisan

The USA differs from most other countries in that expert witnesses can be partisan unless they are hired by the court.

I have rebutted reports written by such experts, and my experience has been that the best way to counter a partisan expert is to be demonstrably non-partisan. When an expert says in effect “I formed my opinions soley on the basis of my experience”, and remind everyone of their illustrious credentials without applying analysis to evidence, then their argument is vulnerable to a well-articulated explanation of facts and findings from which opinions follow, given by the other side’s expert.

I normally consult with clients about how facts might be presented and construed, and the strengths and weaknesses of an argument from a technical point of view. However, my opinions are based on fact, I detail my reasoning, and my findings can be reproduced from the evidence. My opinions are defensible. Shills cannot compete against this approach.

While it is regrettable that the USA is out of step with most of the rest of the world in allowing partisan experts, the opinions of partisan experts tend to be disregarded in favor of opinions from trustworthy experts.

Concurrent Evidence

In other parts of the world, experts from both sides can testify together at trial, in a procedure known as concurrent evidence. They discuss the case in front of the judge, and respond to inquiries from the magistrate(s) and attorneys from both sides of the case,

I participated in such an interchange when I was the lead ERP software expert for an ITC arbitration based in Paris. A tribunal of 5 arbitrators asked me and the opposing expert to stand before them, and they questioned us together. Discussion was encouraged. My experience was quite positive.

The other expert was shown to be partisan. While we underwent the procedure of giving concurrent evidence, I reminded the court that the other expert had not provided any evidence to support the assertions upon which his opinions were based, beyond “Because I said so, and I am an expert!” His opinions were soon dismissed, while mine were accepted.

This is the room at the ICC in Paris, France where I was questioned by a tribunal of 5 arbitrators.
This is the room at the ICC in Paris, France where I was questioned by a tribunal of 5 arbitrators.

Judge Alsup

“The bought-and-paid-for experts will say anything”
“The bought-and-paid-for experts will say anything”

William Alsup has been a United States District Judge of the United States District Court for the Northern District of California since 1999. A Law 360 article published January 7, 2021 directly addressed the issue of partisan experts. The first sentence in the article reads:

District Judge William Alsup appeared unlikely to let Finjan Inc. skip out on Juniper Networks’ $8.65 million legal bill following its defeat at trial, calling out Finjan on Thursday for changing its patent infringement theory to inflate damages and lamenting the “standard patent BS by bought-and-paid-for experts.”

Elsewhere in the article, Judge Alsup is quoted as saying:

The bought-and-paid-for experts will say anything. They will say anything, on both sides. I don’t trust a word of that.

It may be legal to be a partisan expert in the United States, but that does not mean it is a good idea for an expert to conduct themselves that way. Experts that prostitute themselves are no match for against a competant and demonstrably impartial expert.

Common Business Practices Can Cause Experts to Lose

Most senior managers in large firms are used to tightly controlling their subordinates. Contractors and employees are saddled with onerous terms because they are often unable to make significant changes to those terms. This is considered to be ‘business as usual’ in many parts of the world.

When engaged under these terms, an expert invariably must adopt a partisan stance. Engaging experts this way makes them vulnerable to a serious attempt to disqualify them.

I am non-partisan expert. My standard Terms and Conditions document details how my relationships with clients are governed. All clients must agree to these terms, without exception. The document has been carefully crafted to ensure that my opinions are free of influence. This allows me to take on controversial cases, and work for either side.

Experts can only be effective if their independent opinions can be expressed and believed.

Experts Must Stay In Their Lane

The phrase ‘stay in your lane’ is used as a term of admonishment or advice against those who express thoughts or opinions on a subject about which they are viewed as having insufficient knowledge or ability.

About a year ago, I was contacted by an attorney who represented a high-profile individual, whom he described as ‘radioactive’. This person had already been found guilty of various matters, while others were ongoing. Would I be interested in being engaged by him as a software expert?

I told the attorney that I, as an expert, am not one to pass judgment. My job is to respond to questions put to me by independently examining evidence, performing analysis and reporting on my findings. It would be inappropriate for me to attempt to do the work that a judge or jury would perform.

I also said that my opinions would be based on my own first-hand examination of the evidence and subsequent analysis. My opinions are often qualified by the probability of certain evidence occurring by chance.

If his client was concerned about what form my opinions might take, I suggested that they quietly engage me before declaring me as an expert. I would examine the evidence and provide a preliminary opinion in confidence. They could then decide if they wanted to declare me as their expert.

Critical Review and Dress Rehearsal

For an expert to be effective, it is not enough to be competent, trustworthy, examine the available evidence, perform the appropriate analysis, and develop defensible opinions. To be effective, an expert must also articulate the issues succinctly and clearly for their audience.

As a software expert, I normally discuss my notes verbally with my client, and then draft a report. Attorneys I work with normally ask me questions throughout the engagement. For example, they might ask me “Mike, you say such-and-such, but someone might understand your statement to mean this-and-that. Is that what you mean?” My response is often something like “No, not at all, you see there are other factors to consider…” By discussing the issues in this way, the attorneys learn a lot about the technical issues, and I greatly improve the way I express my opinions.

This process gets more intense when preparing for deposition or trial. Often we roleplay: one attorney takes on the other side’s possible point of view, and another attorney argues as themselves. Then they cross-examine me, as the expert. We then critique each other on what was said, and how effective the dialog was.

It takes a lot of preparation to be able to readily provide clear, succinct answers to questions. I greatly appreciate the time I have spent preparing for testimony with the attorneys that I have worked with. As a result of our time together, my opinions were expressed effectively and all have been accepted.


The articles in this series explore topics of interest to attorneys who are contending with cases involving intellectual property issues of software or hardware. This article discussed what ‘winning’ and ‘losing’ looks like for a non-partisan expert, how that differs from how attorneys win and lose, why non-partisan experts can succeed against partisan experts, common business practices that affect an expert’s success, and preparing for testimony.


I would like to thank Eur Ing Professor Geoffrey M. Beresford Hartwell CEng for his thoughful review and advice.

Contact Mike Slinn

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