A bit odd that you would remain on the aircraft for 3 hours after landing if it was a bomb threat maybe?
I was on a Miami-London PanAm 747 in 1985 - we turned round over the Atlantic and diverted to Gander. We vacated the aircraft out in the middle of the airfield, where it remained until after the deadline. Later we were all asked to identify our checked baggage, which was reloaded, and we continued on home the next day - with plenty of unaccompanied bags staying behind. The crew were informative throughout including stating that it was bomb threat during the initial diversion.