A/C Compressor won't hold freon

Local Subaru dealership installed an engine short block under warranty
because of a call back notice.
Went fine, except post installation (couple of months), a maintenance
mechanic noticed the A/C Compressor was loose.
Returned to the dealership who confirmed it was not tightened down on re-
installation. Tightened down under continued warranty work.
Now A/C won't work. Back to the dealership.
Dealer service says compressor is cracked and won't hold freon.
Says it is unrelated to faulty re-installation.
A/C worked perfectly pre-short block.
Now has never worked post-short block.
Could the bouncing around loose cause the cracks in the compressor?
They are supposed to last 10-12 years....
Thanks for the help.