Wasn't that his plan from the start? He probably played it well, apart from the fact that maybe he shouldn't have circulated his concerns using the company's internal tools, he could have written a blog post.
No, his "plan" was to have a discussion.
>He probably played it well
So, not only assuming ulterior motives, but taking them for certain too...
Well, he is an excellent Chess player @ 2300 ELO. He might have had a complex plan. Which might just have been to put up the memo while Google was being investigated, not necessarily to benefit from getting fired.
Besides that, is suing google a sure thing? I bet they have the best lawyers.