Presumably he must've had a good view of events from his dugout. From the Guardian:
"UNITED FANS TO BLAME FOR LENS AGGRO"
Any possibility that tonight might be an opportunity for reconciliation between Lille and Manchester United after the explosive first leg in Lens a fortnight ago vanished in the preliminaries yesterday when the Lille manager, Claude Puel, and Sir Alex Ferguson exchanged words that could not be considered pleasantries.
Ferguson said Lille are portraying themselves "as a little club against a big one who are bullying them. Inevitably that stance puts pressure on a referee." Puel responded by saying Ferguson has been "putting a lot of pressure on - in France we are more interested in respect between managers".
More controversially, Puel accused travelling United fans of being "in possession of counterfeit tickets" in Lens and of being "violent" while there.
"The facts are there for everyone to see, so it is difficult to see why it is Lille's fault. Since the first match, we have heard a lot of things from the Manchester United side. But the situation has been created by them."