Shady wasn’t hit immediately at the hand-off in most cases, he refused to hit the hole (however small or fleeting), IMO.
http://www.espn.com/blog/nflnation/post/_/id/123542/inside-slant-running-back-cliff-after-age-27
Here’s an older article I found that presents the data. The RB age cliff has been discussed for years in fantasy football, there are lots of articles on it.
I was only aware of an infraction, didn’t know what it was for. Either way, I don’t recommend paying a guy top dollar for his locker room presence. But it seems like Beane has already committed to Shady so we shall see what he has left.