Geoff Toovey's frustration at a surprise defeat to Canterbury on Friday night was compounded by an altercation with a Bulldogs supporter at ANZ Stadium.

The Manly mentor clashed with the fan at the half-time break when he chose to head to the dressing room by walking from the coach's box down through the western stand rather than take the escalators and steps inside the venue as most coaches do.

"I reacted to some lunatic. I shouldn't have. A few words were exchanged," Toovey said after the 23-16 loss. "I'd rather do that [walk through the crowd]. I don't mind mingling with the fans. I suppose he just got under my skin. It was very silly of me and I apologise for reacting the way I did."

After an underwhelming performance by his men Toovey could at least find some humour in the exchange with the Canterbury diehard. Asked what the fan had said to him he replied: "I can't remember."