Hughes, 28, said: "I do think in that particular incident, he was getting wound up. He swung a leg at me before the butt. He looked a bit frustrated and I felt it was more of his doing to get head-to-head and not mine.
"It was the usual sort of scrimmage you get at a corner, especially at the end of such a tense game. You often get that. A push and a shove led to another and myself and Ronaldo squared up to each other.
"The last thing I thought was that either of us were going to get sent off when we went face-to-face. You often see footballers doing that.
"Whether he meant it or not, he leaned in a little bit and made contact with me. The ref was standing right there and he saw fit to issue a red."
Hughes added: "If you give a team like United time and space they'll kill you, so you have to be physical. But I certainly didn't try to set a trap to get him sent off, as Ferguson has said.
"I was more concerned about trying to stop Ronaldo's run for the ball as he's dangerous in the air. What happened was just one of those things.
"I've never thought of Ronaldo as a hothead. None of the players think so - otherwise he'd be getting targeted every week, which isn't the case.
"He's a phenomenal player who usually lets his football do the talking. But I don't take what Fergie said as an insult. Alex is a wise man who knows the game inside-out and he'll have known situations like that when you play against such good players.
"You don't want to wind them up but you try to unsettle them, close them down and harass them in a fair way."