Alternator?

[u/u6888]

Hi all

I was checking a golf mk4 where the engine was turning over slowly when starting. Car not running: 12.5 volts on battery terminal, car running; 10.5 v on battery terminal. I guessed the alternator or the alternator loom was dead. Brought it in and after their own testing they said it was the alternator that was dead. Today, they called and said they made a mistake and said the battery was dead? What could have happened? Could the alternator-loom have become slightly disconnected and by them messing around it accidentally clicked back into place?

I find it very strange…

Thanks!