I don't blame Crabtree for pushing the guy off when he had a hand full of his jersey.
However, in the end, the Niners have themselves to blame. The first Raven TD came after an offsides call on San Fran negated a failed 3rd down play. Then in the 4th quarter Culliver got a pass interference on 3rd down which led to a Raven FG.
You just can't make those mistakes in a game of that magnitude.