The general practice in most hotels which I am aware of is to change the bedding whenever a new guest checks-in, if not every night. It's hard to imagine how a previously used condom could end up in new bedding.
There is nothing conclusive that the herpes came from the condom, let alone a previous guest, although that is what is clearly being alleged.
The condom was from "their" bed (implying the boy's family). I would be testing the family members that slept in the bed the night before, and other family members, for herpes as a part of the investigation.
I am reminded of the Wendy's finger in the chili story from a few years ago. Harrowing on the surface, but a lawsuit scam in the end...
In any case, it sucks for the poor innocent kid...
ADG