Ireland head coach Andy Farrell said “you have to be careful what you say” but he did not understand how the yellow card was upgraded by the match officials.
After a delay getting the pictures on the big screen at Solider Field, which is the home of American football side the Chicago Bears, match referee Pierre Brousset and his assistants looked over the incident on a small monitor on the side of the pitch.
Foul Play Review Official Dan Jones recommended to Brousset that it should be upgraded to a 20-minute red card.
Iain Henderson was introduced to restore Ireland to their full compliment after the 20 minutes had passed, and Ireland led 10-7 at half-time before New Zealand ran clear in the closing stages.
Beirne will now face a disciplinary hearing and any further action could rule him out of Ireland’s remaining autumn games against Japan, Australia and world champions South Africa.
“I’m all for the safest way possible for this game to move forward, so you’ve got to be careful what you say in that regard,” Farrell said.
“But to me, if you look at it in real time, I don’t know how it was transferred to that.
“They’ve obviously got their reasons, and I’m not privy to that.”
Farrell also felt that it should have been reviewed at full speed and not in a slow motion replay.
“You can have a look at it from all angles, really, but the only way to look at it is in real-time.
“It doesn’t matter anymore, does it? We’ve got a red card, and we actually dealt with it pretty well to be fair.”
