Trailing 2-3 and with momentum on their side, Kavanagh blew the final whistle just as Antoine Semenyo took position in a good, attacking position to cross.
Iraola said afterwards: “I think there are no big key decisions that he has made mistakes. I complained about the third goal because I think it's not a foul to (Jurrien) Timber.
“He tries to turn, we don't touch him and he goes to the floor and the goal comes from this free kick.
“But it's not about this. It's about the stoppage time minutes. He has given six. He has shown also a couple of yellow cards at the end to Junior Kroupi and Amine Adli, soft fouls.
“We can discuss if he's a foul or not, but very soft fouls. That gives them, for every yellow card, maybe the right to lose one minute, the right to lose another minute and then straight away six minutes, he doesn't give any seconds.
“We have Antoine going inside the box, one against one, to finish with all the team there.
“I think it's common sense. You cannot whistle in that moment, the end of the game. No, he was arguing that in the first half he did something similar.
“But I've just seen it before coming here. He gives Odegaard the chance to cross, he gives Hincapie the chance to cross and then when they play backwards, he whistles.
“So I think we were disappointed, the management and this.
“But it's not like a game that they have affected, we’ve complained West Ham, Sunderland, games have been like key decisions really affecting the result. Today, we complained, but I don't think it's affecting the result massively.”