You can also tell if someone is remotely connected to a computer by doing this:
1. Open Administrative Tools
2. Open Computer Management
3. Expand "Shared Folders"
4. Click on "Sessions"
It will list any remote connections in the right-hand pane.
Is it possible that your husband selected "Home" or "Work" when the dialog
popped up to ask him to classify the network he was on? If so, he would have
opened the computer wide on the hotel network.
Your question may already be answered in Windows Vista Security: