Ferguson branded Cole's challenge reckless in the aftermath of the game, although referee Phil Dowd decided it was only worthy of a yellow card.
The only conclusion the Scot could draw from that decision was the officials did not see it, and he is not entirely sure why his side did not get a penalty either.
"I am confused," he said. "I don't think the referee could have seen it.
"It was a spur-of-the-moment challenge by the player, reckless yes. But I don't know how the referee could have possibly seen it and the linesman wasn't in any better position.
"I don't know what the rules and regulations say about that when the ball is out of play - there seems to have been some discussion about it not being a penalty because the ball was out of play.
"I wasn't aware of that - I don't think anyone was."