The Preston captain was dismissed in the 36th minute after tangling with Boro’s Sam Morsy, a decision which altered the course of the game.
A Jordan Storey own goal and Marcus Tavernier header gave Boro the points, while visiting boss Alex Neil was sent off after complaining to the referee at half-time.
When asked about the incident after the match, Warnock said: “I'll have to do an Arsene Wenger, It was the least of my worries at half-time and full-time so I've not even seen it.
“I heard them complaining on the bench but the ref had a good view. It's difficult playing against 10 men, for whatever reason they come more solid. We played some good stuff in the second half.
“It was all about winning tonight. We had the performance against Stoke, tonight was about the three points.”
Neil offered a different view on Browne’s red card. “It’s an extremely poor decision,” he said.
"I have seen it back. Sam Morsy hits him with his forearm on the back of his head, he is right in front of them. Alan instinctively reacts because not only has he been hit once, it’s twice.
“It is hard to accept and understand how the ref and assistant can see Alan’s part but not Sam Morsy’s part.
“It changed the game in their favour. Their player is the aggressor and our player reacted in that instance.”