This.
And by most people's standards '1 in 2' is a very good ratio for a striker. Barnes is at this level now, which is certainly adequate for the type of team he plays in.
I did not see the incident itself (i.e. the punch) but the subsequent events lead me to believe it was an overreaction on Barnes' part. I know if I was punched by someone and it left me lying on the floor unable to get up for a good few minutes I would not be able to immediately carry on playing...