Doctor in the House S09E13 - Identity Crisis

The animosity between Duncan and Maurice Griffin intensifies when Griffin gets slapped by a nurse's irate mother after she is told he is Duncan. Both doctors squabble over who should have priority in the operating theatre with their respective patients but it appears they have mixed the patients up and performed an operation on a man who does not need one. In fact the orderlies mixed up the name tags but Professor Beaumont allows the doctors to believe they are in the wrong so that he can transfer them - and Stuart-Clark - to Casualty.