At the very least it cost us 3 points. It was an intentional pre-snap decision by 9 too. So it was on him, he hurt the team there, and McVay needs to make sure next time around he will go through his reads instead of making the call based on a rushed look pre-snap.
Fixing that is a big deal. Points are hard to come by in games like that.
This is not to say that I'm down on Stafford because I am not. I am happy with him and think he is still working toward his ceiling in this offense. Just keep fixing and streamlining the mental process and get this guy fully locked in to where we are maximizing his good and minimizing his inner gunslinger.