Newcastle boss Alan Pardew and Sunderland counterpart Martin O'Neill found themselves embroiled in a war of words after a tempestuous 1-1 derby draw.
The game saw one penalty scored, another missed, eight yellow cards, two red cards on the pitch and a third in the tunnel, a last-gasp equaliser and repeated confrontations between the respective benches.
Asked about the straight red card Lee Cattermole received for confronting referee Mike Dean after the final whistle, O'Neill said: "Possibly in mitigation we had heard that some of their staff had visited the referee's changing room at half-time."
Pardew, whose goalkeeping coach Andy Woodman was dismissed at half-time after a spat with Sunderland fitness coach Jim Henry, insisted no-one had visited the referee.
He said: "I can tell you that's completely untrue. None of our staff was allowed in the referee's room. No-one tried to enter it and no-one entered their dressing room. I heard that rumour and it's not right."
Sunderland's Stephane Sessegnon also saw red for elbowing Cheick Tiote. Nicklas Bendtner put them ahead with a penalty and Newcastle's Demba Ba missed from the spot before Shola Ameobi snatched a point for Pardew's side.