Aer Lingus 146
There was a similar incident at STN involving an Aer Lingus 146. The baggage loaders always positioned the baggage trolleys very close to the hold. I can't remember if it was the front or rear hold but to cut a long story short the loaders pushed the trolley to fast and it struck the aircraft piercing the skin. The aircraft pushed back from B21 with all four engines running when one of the loaders involved informed someone of the hole and the aircraft returned to stand.
I remember one of the loaders involved left the company, not sure about the other chap. I'm sure if they had just informed someone about the accident they would have been given a warning or something similar. This probably took place around 1999/2000.