Replacement prop Pierre Schoeman received a red card for a lead elbow on Leinster flanker Dan Leavy during the Blues 31-7 win over Edinburgh at the RDS on Saturday.
Schoeman replaced Scotland international Allan Dell 10 minutes after the restart but headed back to the sidelines just over 20 minutes later after he led with his elbow from a routine carry just inside the Leinster 22.
Referee Dan Jones said that he had no other option but to send Schoeman off, a decision that was agreed upon by television match official Simon McDowell.
Edinburgh head coach Richard Cockerill said that he believes that Schoeman’s elbow was accidental but that ultimately players must accept the consequences of their actions regardless of intention.
“It is a red card these days,” said Cockerill.
“You’ve got to protect people. I don’t think it was malicious from our guy if he’s dropping a fraction but look it happens. It happens. It’s an accident more than anything and we know the consequences if it happens.”
The former England international said that he was happy with his side’s performance given the relative strength of Leinster who had 13 internationals in their starting XV.
“I’m happy with the performance to a degree,” he added.
“Christ they’re a good side. They picked a good side and we worked bloody hard and we got to come to places like this and compete and we did. We’ve got to keep growing our team and learning from night like tonight.”