Barnsley boss Mark Robins blamed the controversial dismissal of Paul McShane for allowing Middlesbrough back into the game and claim a 1-1 draw at the Riverside.
McShane was shown a red card for his part in a flare up with Boro midfielder Kevin Thomson.
Robins said: "I don't think either (McShane or Thomson) should have been sent off. It was a classic case of handbags.
"The referee could have avoided the problem by giving a free-kick either way earlier in the build-up but the incident itself was just routine bodily contact as they battled for the ball. It was 50-50.
"What happened after that with players from both sides was 50-50 too and possibly he could have sent the Boro man off too. For me neither of them should have gone.
"But what was disappointing was that with us being down to 10 men swung the game Boro's way. It was their only way back into the game.
"We dominated the game for long spells and we should have been out of sight by half-time.
"But that has been our problem. We have gone to good teams like Boro and even QPR and created good chances but not finished teams off and paid the price."
Middlesbrough boss Tony Mowbray agreed with his Barnsley counterpart.
"The fracas was just exuberance that boiled over," he said.
"Sometimes when you get competitive and macho players fighting for the ball like that there is pushing and shoving. The problem comes when other players get involved to pull each other away from the fracas.
"Whatever happened you have to say we benefited. That fired up the crowd a bit and maybe it fired up the team as well and gave us a bit of a psychological push in the closing stages against 10 men.
"I don't think we played well at all. We started slowly and we looked leggy and tired at times and we weren't playing short passes when we should, or long passes when we should.
"But the positive I'll take from this is the desire this team is now showing to come from behind and the desire not to lose football matches.
"I think it is four games in a row at home we have come from behind now and that is a big, big positive."