I would say he is totally fucked. It's very likely that he did leave Google with a big pile of their IP that he thought could help with his startup firm. By buying his startup Uber will have acquired a lot of backups with the files of IP festering within them so the only sensible thing for them to do is to distance themselves, fire him then sue him to recover the legal losses and costs which will probably amount to every thing he got from selling his startup to them. That is the least of his problems.
Google will place a very high monetary value on their IP making the theft a major felony with criminal charges ensuing. They might be able to reasonably evidence that he accessed all the files found at Uber before leaving and Uber may be able to evidence that he imported it into his startup firm (particularly if someone at his startup feels that they didn't get a deserved cut when it was sold to Uber and wants payback).
With both Uber and Google out to get him and the fifth amendment being his main defence standing between him and jail time he is very very fucked indeed.