Hardly a head butt. He moved his head towards a player that was aggressively pushing his head towards him and Vertonghen barged through a bunch of players to incite him.
I'm not saying he was guilt free but it was all instigated by Vertonghen and the over reaction of him & Dawson.
Spurs needed the third goal. Disgraceful sending off...Vertonghen went looking for that and conned the ref. Feel sorry for the chap sent off.
...I thought if fouls occurred in the box it was a penalty regardless whether the corner kick or free kick had been taken?