Trunk won't open
 

I just sold my 2007 GS350 to a friend. The car has 279,000 miles, and I owned it since new, with very few problems. Right after my friend got it home, he called and said he couldn't get the trunk to open. I had opened it earlier that same day. I walked through all the ways you could open it (with a button in the door to the left of the steering wheel, using the fob and pushing up on the area above the license plate, etc.). He had tried all those things, to no avail. I've never had an issue with the trunk, and feel like something got reset somehow. Any ideas on resolving this issue?

Check if somebody has accidentally pressed the valet switch inside glove box...