Why not pass your word to treat this little matter as a joke?
It's the simplest way.
Go up to your room, change your clothes and shave, have a drink with us, and take the morning train to town.

It's not worth while risking your life for the sake of a little bit of revenge on us for having gone too far.

I admit that we were wrong in keeping you here.

You terrified us.

Forrest has more enemies than friends and I am unknown in London.
If you went to the club with your story, people would believe it.