So the official sources say this poor gentleman had passed out in the street, then got decapitated by a passing coach which pulled his head off via the wheel arch.

I was hearing earlier rumours on whatsapp that criminals had thrown the head from a moving car in order to send a warning about drug debts... seemed far fetched even if Dumbiedykes is just down the road.

Uncensored images of both the head and the headless corpse are doing the rounds on snapchat. Also CCTV footage of a group of drunk people who appear to play with the head by picking it up, and then one of their party "teabagging" it. Reminded me of Tropic Thunder when Steve Coogan's character dies but the other characters all think it's a prank.

Edit: added missing "the head"; clarification

"It also left a man's decapitated body lying on the floor next to his own severed head. A head which, at this time, has no name."

It's The Quickening.