Freddie Sears gave the visitors a 25th-minute lead against the run of play after the Blades were caught on the break following a corner.
Harry Maguire equalised in the last minute of the first half thanks to an error from keeper Sam Walker, who helped the ball into his own net from the defender's shot.
Dunne said: "I think it's a decent point. Overall, I think a draw was a fair result.
"We decided to leave more players up at corners. We felt it was a good ploy and we got the goal from it.
"Sanchez Watt took an eternity to pass it but that's his quality and it was a quality finish by Sears.
"We wanted to attack them and I felt that we did that in the first half. We started the game with quality and ended it with true grit.
"The game plan worked exceptionally well. Just up until their goal, I thought we were comfortable.
"The onus was on them to come out, certainly in the second half, but I felt that we showed a bit of resilience.
"We didn't carry too much of a threat going forward but we stayed in the game, competed and at times played some really good football."