I am not sure its fair to put this on him, the QB's have not executed at all no matter what the call is. I do blame the coaches for concluding Peterman was the starter and McCarron was expendable. And Allen was ready when he was not.
However one area where the Bills are close to the bottom in the league is holding, illegal formation and false starts. I think this is coaching, especially illegal formation. They need to get that crap cleaned up ASAP.