What? Seriously?
Yes!
In the Extras section they have these little snippets to close up some plot holes and tie up loose ends. So there's one where Ed explains how Shaun found him and brought him to the shed.
And there's one where Diane explains how she made it out alive. Turns out David's leg was good for more than just a weapon. She rushed out there, busted some heads, then realized she was in trouble and ran for the nearest tall tree. She climbed up and stayed up there until rescue parties found her. She avoided starvation by... well... eating his leg.
After which, she apparently moved to another city in England and now lives with her aunt. She also, apparently still keeps in contact with Liz and Shaun via Christmas card.