Originally Posted by
MADPhil
That is rather odd because there is no passport control to leave the UK and since they were still in the UK there should have been none to return from the gate.
right, but they were essentially removing him from the airport because his ticket was no longer valid, and so the only way out of the airport would be how arriving passengers come in. They aren’t going to send him through the security check backwards in order to remain in the UK, they are going to escort him through passport control. MAN airport is a strange series of windowed hallways, this does make sense in context to this (and probably most) airports