A fan is a fan. You can't control the actions of 30 odd thousand people, or legislate for every one of them.
Ashley Williams, on the other hand, is an embarrassment. Lost his head completely, as a senior player, and should've been given a red. I find it a bit ridiculous that anyone's defending him.
Yes he should've been by today's standards, but he wasn't. Just put yourself in his shoes for a moment. He's had a mare of a season, he's been criticised by his fan base on a regular basis and he's just played a part in costing his national team a chance to get to a WC. He knows how important this game is, he's become frustrated at the tactics of the opposition. Sometimes your head goes. I've done things like that on a rugby pitch in high pressure games. We're all human. We've asked for the players to show a bit of passion, they have. If Mo Besic or Gana had done it I'd support them too. Now let's see if there's a reaction against Arsenal