Defect. "One nav light inop on left wing tip"
Action. "Crew will not accept MEL, so new bulb fitted, still inop"
Aircraft N/stopped and crew and passengers to hotels.
Working party on route to troubleshoot and fix inop nav light.
This appears to be the way some see things going.
One point has crossed my mind, this MEL item may of been used many many times in the past for the same said pilot reported defect, when defect was fixed by changing a relay, did no alarm bells get sounded !