Dean Hammond, Craig Mackail-Smith and Wayne Bridge were the goalscorers for the Seagulls.
The result followed victory at Charlton on Boxing Day and then at Wolves on Saturday for the Tractor Boys.
"We didn't play particularly well but I'd have taken seven points from our games (over Christmas)," McCarthy said. "I always look at the bigger picture.
"I was brought in to keep the club in the league and pick up points and that's what we're trying to do.
"I admire the players. The way they've gone about their business has been amazing.
"To have got us 30 points by January 1 is terrific. They've been remarkable and it's been a great turnaround.
"We've got ourselves in a good position and just because we've lost one game doesn't make us a bad team.
"It was one of those days. When one of our players made a hash of a clearance at the end I just laughed, because I thought that summed it up for us.
"We conceded from a corner which was disappointing, because it's unnecessary, and when they scored it took something out of us."