Typically there is a wireless icon at the bottom of the desktop screen
in the system tray. Clicking on it brings up a box with the wifi manager.
But you'd think he's seeing that, if he can see the list of networks.
All the ones I've seen, when you can see the list of networks there is
a refresh button or scan or something that scans and updates the list.
If nothing else, rebooting would do it.
It's also possible that somehow the network got marked to ignore or
something, so that it won't show up, but seems unlikely.