I wouldn't worry about this. The situation is out of your control, so if the adcom/Kroll really feels the need to contact him, then they will surely ask you for another phone number. But if you want to be safe, e-mail the adcom and let them know, I'm sure this stuff happens all the time!
But more than likely, you're probably safe doing nothing. I think there is a slim chance that they'll actually try and contact him.
GMAT Club Premium Membership - big benefits and savings