There s a 777 skipper at EK who in a previous job flying for an Asian cargo operator had an emergency landing and precautionary disembarkation on the runway in Germany. All 4 pilots still in pyjamas. Initially charged with endangering the safety of the RFF as they didn't know who the flight crew were and also went into the aircraft to search for said flight crew. A consequence of this charge could have been having flying licences revoked in Europe and Asia.
I don't allow flying in Pj's on my flights. As Harry says it's unprofessional and you have no time to change in the event of a diversion