Board Thread:Speculation House/@comment-27404492-20170708180328/@comment-28522425-20170913140533

Somewhat related the idea of WF members seeing Weiss being friendly with Blake:

I actually have a theory that, when they were on the train, Blake either injured the Lieutenant, or just depleted his remaining Aura, causing him to be severely injured in the crash.

Seeing one of his most loyal followers hurt because Blake was protecting not only a human, but a Schnee (as the last we actually see of him is running towards Blake who is carrying an injured Weiss away), was the last straw for Adam, who then decided to make Blake's lige hell.