There's been previous between Wenger and Allen:
http://www.telegraph.co.uk/sport/foo...line-duel.html
And here's a picture of the "incident"
http://d.yimg.com/a/p/sp/getty/51/fu...-506264326.jpg
http://cache.daylife.com/imageserve/...61a9/1024x.jpg
tbh, I wouldn't want to shake hands with a cunt like that either. Wenger is too ungracious in defeat too often, but on this occasion I don't care that he didn't shake the wanker's hand.