AEG W1270 tripped main fuse and remained locked

Hi,
our washing machine tripped the main fuse (not the circuit breaker) for the flat. As there was still water in it and could not open the door, we switched it on again and after a few trials (blowing the fuse 2 or 3time) it finished of the program (rinsing and tumble dry phases), but at the end the door remained locked. I had to remove the lock to open it.

Could it be that the lock produced a short circuit? If not is it a conincidence that the lock failed? And what are the likely reasons for the fuse tripping? Clearly the main motor and pump circuits function well. Could it be the heating element producing a short circuit? I though when it fails, the filament is broken and is not conducting.

Many thanks,

imre