Google wins this one
It starts to make sense when you lay out the timeline, which is as follows:
t=0: Levandowski works for Google. He does their self-driving car stuff. He downloads 14 THOUSAND files from Google. I somehow doubt these are cat videos, and the fact that Google are suing suggests they have evidence that it was more meaningful. A git repo maybe?
t = 30 days. Levandowski quits and starts his own self-driving car company. I somehow doubt that this was a decision made between t=0 and t=30
t = few months. Uber buys Levandowski's company (Otto).
I can well see why Mr L has taken the fifth. He's looking remarkably like he stole IPR from Google, got Uber to unknowingly pay for it via the acquisition of Otto, and now must have be enjoying some serious lawyerly arm-twisting from his employer, who stand to lose a heckuva lot of Google's claims against him are proven.