Jack Ross argued the referee got the game-changing moment in his side’s promotion showdown with Pompey wrong.
The Sunderland boss felt referee Peter Bankes was wrong to dismiss defender Glen Loovens after the restart as the Blues triumphed 3-1 on Saturday.
Loovens hauled down Oli Hawkins, who was clear on goal, in the box, leading to the 35-year-old being given his marching orders before Gareth Evans ruthlessly dispatched his 48th-minute penalty.
Ross had no doubt the game spun on that key incident, which marked the start of four goals in a frenetic 15-minute period.
And he felt Lee Brown should have walked for a first-half challenge on George Honeyman.
Ross told the Sunderland Echo: ‘You are right to point the flow of the whole game changed with the red card decision, we were good prior to that.
‘We were very controlled first half, and had a group in there at half-time who believed they would replicate that second half and go on to win the game.
‘You are playing against a team who are top of the table and in their own stadium, going down to ten men will have an impact.
‘I get the benefit of watching incidents again, the red card I would argue isn’t a red, under the new guidelines, there is no genuine attempt to win the ball but there was no attempt to bring him down, it is a coming together. It is a penalty kick.
‘The incident first half, have we been punished for similar incidents? Yes we have, simple as that.’
Ross’ argument over the Loovens dismissal centred on the rule change two years ago which stated players shouldn’t be automatically sent off when committing accidental fouls which deny a goalscoring chance. The Scot felt that was the case with his defender.
He added: ‘I don’t know, I need to clarify the wording of the rules, that can determine how it is looked upon.
‘I know the rules have changed to avoid that double jeopardy, to be honest at the time I couldn’t see clearly so thought he pulled him back.
‘Watching it again, Hawkins does well to come across him, but the legs catch each other, my understanding is that it isn’t a red card.
‘I don’t know the exact wording, that will have a bearing on whether we decide to that or not.’