To summarise: if he's not a thief and didn't steal then where is he? Where is his legal challenge, which remember he originally threatened, to claim back his ill gotten plunder?
I answered that. He's not a thief according to the "code is law" system. He might very well be considered a thief under "human paper contract law". As the "code is law" system has been broken by the fork, the legal system in which he did his legal things has retro-actively changed from the law into something akin of the "decision of the King" (or of the mob). As this whole circus of "the code is the law" is in ANY CASE probably not valid from a human law point of view, there's no point for him to go to court. So why did he say something that wouldn't make sense in a human court (and he must have known that) ?
I have a theory of why he might have issued these legal threats even though he probably didn't have a foot to stand on in the human law frame: his goal was not to become rich, his goal was to break ethereum. Now, by threatening with legal action, he made it much more probable that the OTHER SIDE (the DAO bagholders) would also threaten with legal action if nothing was done, and hence use them to scare the hell out of the ETH foundation, so that they would break their system with a fork or something. As such, what should have been a DAO-limited disaster has affected ethereum itself, so that these guys showed that not only their coding language was tricky to use, but moreover that their whole block chain was rewindable, so that in the end, NOTHING remained of the ethereum proposition: a buggy star application, the DAO, a tricky programming language, and on top of that, a broken block chain and a broken promise of unstoppable contract.
In other words, his threat of going to court was nothing else but a bait to stimulate a fork and screw up the whole system. One cannot say that he failed, but in any case, it was a win-win situation: by doing so, if the ETH foundation would have stood firm on its principles, he could have cashed out severely, or he would have lost his stash, but the ETH foundation would have screwed the last bit of credibility in their principles, which was his announced goal.