Did I represent the business executives in their personal capacity? No.
Did my presence in the interview aid them immensely in their personal capacity? It sure as hell did. And, it also aided the FBI in understanding the truth.
People just aren't careful with how they phrase things, and they are not careful in paying attention to exactly what others ask. Lawyers assist with that.
Interview #1:
Agent: "Can you confirm that X is true?"
Jim (an interviewee without attorney present, thinking to himself that his company database says X is true, answers confidently): "Yes."
Interview #2:
Agent: "Can you confirm that X is true?"
Jim: "Yes."
Attorney (knowing that answer is too simple, and may lead the FBI to ignore factors they should consider): "Jim just stated that X is true. Jim, is it accurate to say that you have concluded as a business matter, that X is true for the purposes of our business proposal? You operate our business as if X is true?"
Jim: "Yes.
Attorney: "And your conclusion was based on an advisory report prepared by junior managers, correct?"
Jim: "Yes."
Attorney: "And you trust those junior manages."
Jim: "Yeeesss..."
Attorney: "And that advisory report was a summary of data taken from our corporate research database?"
Jim: "Yes."
Attorney: "And that database was created by data entry specialists, with some training in this area, but definitely not experts?"
Jim: "Yes."
Attorney: "And although they could have made mistakes in entering that data, you treat that data as if it is true, because you can't be hamstrung by uncertainty. You rely on their competence, even if you don't verify their work yourself?"
Jim: "Correct."
Attorney: "And some of the data sources they use are secondary sources; that is, they are compilations of data we purchase, but cannot verify ourselves as 100% correct, even though we treat them as 100% correct for business purposes. Is that a fair summary?"
Jim: "Yes"
Attorney: "Now, can you actually say that X is true? Or, can you only say that you treat X as true for business purposes, and you are confident in that conclusion......but, there are a lot of factors we need to discuss today if we are to actually confirm that X is actually true, in reality?"
Jim: "Yes. I'm just saying what my database says."
In both interviews, Jim did not mean to mislead the FBI. He wanted to tell the truth.
But, if X turns out not to be true, would Jim be charged for lying to the FBI in Interview #1?...maybe, or maybe not. Interview #2?...probably not. Attorney wasn't there to protect him personally, but the attorney ended up protecting (i) him from prosecution, (ii) the company from prosecution, and (iii) the FBI from being mislead.
The answer as to whether he is prosecuted in the first case hinges on whether the FBI thinks (rightly or wrongly) that it can gain something from him to get someone else...the true target of the investigation. Jim may be innocent of the crime they are investigating, but if they can charge him with lying, they may believe that they can get him to do more for them, to get the real target of their investigation. And, if he has to sell his house for legal expenses, or if he sees them trying to do to his son what they are doing to him, he will plead to anything.