Working in ops and also having worked out on the ramp
if a baggage trolley trashes an a/c, then a delay is almost inevitable, at least whilst engineers assess the damage and to see if it's within limits to depart.
I doubt very much if any reputable carrier would trawl out this excuse to "cover up" any other delays.
Could show you the photos of various damaged a/c that have argued with a baggage loader.
In fact, we've got a a member of our crewing staff who, in his younger days on the ramp, drove a loader into an Air Malta a/c, grounding it for 24hours...He made the front page of the local rag.