Y Tu Mamá También

When does a factual statement about race become racist?  The question arises because an English rugby (union) player called a Welsh player a "gypsy boy" during a recent international.  The Welsh player does indeed come from Romany stock, and indeed has made no secret of it.  So. maybe not a nice thing to say (and indeed the English player apologised for it at half-time) but racist?  If somebody calls me an "English prat" is that racist?  It has been suggested that it's all a matter of intent, but who is to say what a person's intent is.  It seems probable that the English player's intent was to "wind up" the Welsh player, but does that make it racist or is it simply a (perhaps regrettable) aspect of the way sport is played these days?