It can not be john since his hat is already taken by serge and I dont think Phil and Maurice would share his coat.
It must be the hat and coat of serge because as I already said Johns hat is already taken away by serge and Serge is the only person left that has not anything taken away yet. That is only true if Maurice and Phil do not take their own stuff. But it says they accidently grab the stuff of their brothers so it must be Serge´s.