I think we are getting close to the territory of Beane being one of the worst GMs in the NFL. His draft picks, contract extensions, and lack of trading for proper pieces have been abysmal. Below are his highlights, and I am sure I am missing some but man, he is looking terrible right now.
Trading for Diggs - worked out although hindsight obviously shows keeping the pick and drafting Jefferson was way better
Drafting Allen - this is the only reason he still has a job
Notable draft picks over his tenure - Spencer Brown, James Cook, Terrel Bernard, Torrence, Bishop, Shakir, Benford, Teller (traded)