Asked afterwards if Gibson should have been dismissed, Arsenal manager Arsene Wenger replied: "Yes. I don't know why [he was not], honestly."
That brought a tart response from Everton manager David Moyes, who rubbished suggestions his side had come to the Emirates with the aim of roughing up Arsenal.
Both Moyes and Wenger weren't privy to what unfolded in the tunnel but the FA might want to take a closer look at the fracas after a week in which hooliganism has once more blighted the English game.
In the meantime Arsenal must regroup ahead of Saturday's visit to Fulham. Though the draw moves them two points clear of Chelsea and Tottenham, the Gunners have now played two more matches than the Blues and one more than their bitter north London rivals. But with Spurs not playing until Sunday (against Manchester City), Arsenal could increase the pressure with a win over Fulham.
Tottenham not only have City still to play, but they must travel to Stamford Bridge on 8 May, a game that could well decide which two clubs join Manchester United and the Sky Blues in next season's Champions League. Everton are still in with a shout despite last night's draw but they have only five games remaining to make up the four-point deficit on Arsenal.