As an engineer I would say it distorted the engine beams or rear fuselage structure where it is attached, the two beams run across the rear fuselage and are the main structural spars of the stub wings, they are also if I am correct fwd of the rear pressure bulkhead as you could see them through the access door behind the mirror in the rear bog. Not a place you want distortion as the fin is also nailed on in that area.
This might help, see
VC10 Engine Installation