Been there pushing back while we heard it on the radio. Apparently the Icelandic was not all the way parked at what had to be gate 242 at T2B while the 777 passed behind on L on the way to 27R. Think their VDGS did drop out and they were holding short. They noticed ground control that they felt a jolt and ground control told the 777 to hold position and then sent out the service vehicles to have a look. By that time we got our t/o clearance.