Blackburn boss Allardyce could be in trouble after he questioned whether Walton was good enough to referee in the top flight after turning down a Rovers penalty claim at the Emirates Stadium.
Sam Allardyce: "I don't want to detract from Arsenal but it was a blatant penalty.
"There is no doubt in my mind that the position of the referee was excellent.
"He just didn't, unfortunately, give the decision in our favour.
"It is human beings in a very big pressure position.
"In the big pressure pot that is this league, you have got to get the major decisions right otherwise you don't stay in this league too long, not as a manager or a player, so as a referee you have got to be judged the same.
"They are fully professional now so if they are not good enough, we should find someone who is.
"That decision wasn't good enough for me today and it had a major effect on the course of this game."