The simplest answer to you question is the guy has absolutely no understand of how the US legal system works. In China, when you are in any "legal" trouble, whether you actually are at fault or not, if you want to get out of it, all you have to do is "confess". The dude probably thought he could have done the same in the US. This is naivety, but not entirely beyond belief given how backward the Chinese are when it comes to legal matters.
In China you can't run away after you got on the radar of a serious investigation. Maybe he thought the same happens here? Like he thought Apple security is equivalent to FBI or CIA or something.
And then eventually someone told him he can just leave, but by then FBI was already interested?
