Nottingham Forest boss Steve Cotterill criticised Southampton's bench for their conduct after having skipper Luke Chambers sent off.
Forest were trailing 1-0 when Chambers was given his marching orders four minutes into the second half and Southampton went on to comfortably win 3-0.
The Forest defender was shown a straight red card for an alleged elbow on Saints striker David Connolly.
Southampton boss Nigel Adkins had no doubt that Chambers deserved the red card, arguing: "I have seen the incident again and it was definitely a sending-off - but I (also) thought so at the time."
But Cotterill was upset at the reaction of the visitors' bench following the flashpoint incident that did nothing to help Forest out of their critical position.
He said: "Luke doesn't think he elbowed their player. I couldn't complain about it because from where I was I couldn't see properly but I was annoyed at the way people were in the fourth official's ear.
"I don't think it is right. People should walk away from it and leave it to the referee. What I do know is that we should have had a free-kick just before that for a foul on Marcus Tudgay and if the referee had blown for that, the incident wouldn't have happened.
"But it's an indication that just about everything that can go wrong is going wrong for us. These are tough days.
"Although we didn't play well we could have been two or three goals up before they scored but I accept that we were not the better team with 11 men so it was going to be really difficult for us with 10.
"We were up against a side who are flying high, they are top of the league and their tails are up. We have not been scoring enough goals all season so it was going to be very difficult for us."
Even without 17-goal Rickie Lambert, who was serving the second match of a three-game ban, Southampton had too much firepower for Forest.
They took a 26th-minute lead when Guly Do Prado lashed home a rebound after Connolly's shot from Jack Cork's cross had come back off Forest goalkeeper Lee Camp's legs.
And after Chambers' dismissal, Connolly added a second goal in the 65th minute following Dan Harding's cross and then Morgan Schneiderlin produced a 79th-minute screamer to complete the scoring.
Adkins added: "You have to earn the right to play football and we did that today. We gave a very disciplined defensive performance that enabled us to go and control the game.
"Our principle is to pass the football and we did that very well. We have some exceptionally good footballers in this team and they demonstrated that today.
"I know everyone will be talking about the sending-off but I thought we were in control of the game anyway so I don't think that would have affected the outcome.
"We scored three times and we could have had more and to win two successive away games without Rickie Lambert is very pleasing."