Confusion continues to surround allegations of diving made against St George Illawarra players by Sydney Roosters coach Trent Robinson.
The Tricolours mentor and member of the NRL's competition committee has long rallied against the issue of players simulating injury in rugby league in an attempt to earn a penalty.
For the second successive year, Robinson accused the Dragons of lying down on Anzac Day after their controversial win at Allianz Stadium on Monday.
Robinson and McGregor are said to have clashed over the issue in the post-game on Monday and the Dragons coach continued that exchange on Wednesday.
"It was a sign of a frustrated man after the game," McGregor said.
However, star Dragons playmaker Benji Marshall appeared to admit McGregor was encouraging his players to stay down for penalties.
"The rule is if you make contact with the head you are more than likely going to get a penalty," Marshall told Fox Sports' NRL 360.
"The coaches will say it, they say if you get hit in the head stay down because you know it's going to go up (to the bunker).
"It's within the rules, and until they take it out it will be there forever. Every team is guilty of it."
Dragons forward Joel Thompson was asked what he thought of Robinson's comments after his grade two high tackle was successfully down graded at the NRL judiciary on Wednesday.
"It's not my place to comment. It's for those players personally," he said.