A trio of United players, David Beckham, Ryan Giggs and Nicky Butt, were booked for arguing with the referee Mike Riley as frustration mounted with their failure to break down a stubborn and well organised home defence.
Kevin Davies' third-minute header proved enough for the three points as Andy Cole's effort was ruled out for offside and Beckham's free-kick came back off the upright.
The game followed a weekend of similar indiscipline from managers and players alike but Palmer, no stranger to the referee's notebook himself, had sympathy for the players. "I think it's frustration," he said. "They want to win like every team wants to win and when it's not going your way you do get frustrated.
"They're professional players, they want to win the championship. It's to be expected. I'd be disappointed if I was on their side and I wasn't amongst players that weren't happy with things that were going on like that. They have to care. If decisions go against you, you do lose your temper. You can't just switch it on and switch it off. You have to have that passion."
Southampton's victory extended their unbeaten run to six games in the Premiership and kept United well within sight of the chasing pack. Alex Ferguson's team have a five-point lead, but Palmer insisted United remained firm favourites. "I still think they're the best side in Europe," Palmer said. "We've worked extremely hard against them.
"Of all the teams I've seen, consistently they do it week in week out. If you sit off them and let them play they'll destroy you. Before the game starts if you are playing teams like Manchester United, Chelsea or Liverpool you know you have to close them down and deny them space. If you don't do that you haven't got a chance against them, to be fair."