He seemed to be unenthusiastic about remaining, having expressed doubts about the EU in the past.
So in fact, Corbyn may well have swung the vote to Brexit by not pushing to remain as much as his party wanted, which may upset some:
Corbyn should have stood by his anti-EU beliefs. He cucked out. Time to go, Jezza.— Paul Joseph Watson (@PrisonPlanet) 24 June 2016
And it was Rothschild gofer Mandelson who was first to start sharpening his knives on BBC radio this morning.