While at dd's checkup at the pediatrician today, asked the dr. about this whole topic. She has MD after her name, and did NOT say what you are saying. She said that it she'd give the OK after a RID treatment and a comb-through IF, and ONLY IF, the child was brought back in for a re-check. Because if only one or two bugs survived (or had fallen onto a stuffed animal and were waiting there for a new host) the child could still have lice. Also, with just a couple strands of hair with nits attached shedding, the nits could have been about to hatch soon -- then they could hatch where the shed hair lies, and find a new host.
So apparently, just a couple of shed hairs (we shed many per day) in the hotel room, once the nits hatch, could infect someone else. She didn't understand where the 10-day non-contagious thing came from because NEW nits hatch in about 10 days -- but not all that child's nits are brand new. With light hair (which the OP says her dd has), nits will be particularly hard to see.
I really, really hope the OP remembers to say something to Mousekeeping afterward. At ASMU once, we got a just-fumigated-for-lice room once. The carpets had to be cleaned and everything, and were wet for our first couple of days.
The ten day thing comes from the RID hotline (yes I called it about 15 times when my kids had them. The deal is, the treatment kills the live lice and the eggs that have already developed a nervous system. The insecticide attact the nervous systems. The newly laid eggs don't have nervous systems yet so they still hatch in 7-10 days, but the older nits that have nervous systems do get killed by the treatment.