This doesn’t surprise me. I once worked at a site where the overnight security were from Armourguard, and, with one or two exceptions, the guards were not exactly on the up and up. Plenty got booted from the site for sins as diverse as using the phones to make long distance calls to family, napping when they were supposed to be doing their rounds, and so on.
None of them actually got fired, though, just moved to another site. Similarly, we’d find out that new replacement guards had been booted for being up to no good on other sites.