[patrickk]

I'm not an expert at all, but sounds like that would've definitely helped.

The author, Michael Lewis, actually conducted an informal trial in a restaurant, with (neutral) HFT experts, who were even more furious than Serge was when they learned how he'd been treated.

I wouldn't be surprised if non-technical executives in Goldman simply saw a Russian leaving for a competitor, and assumed he was stealing valuable secrets without investigating properly.

Worst part is, even after the details become apparent (see other comments here), Goldman or the FBI are completely unable to admit any fuck ups, and continue hounding him.