I walked past this cycle rack daily for two weeks whilst working away in Leatherhead and on the last day I spotted this.
Having had two bikes stolen this year I sympathise with the owner. It shows in this instance that the thief/thieves were most likely opportunists, given that the wheel is secured with a fairly flimsy cable lock. I would speculate that the owner of the wheel had forgotten to secure his/her frame to the rack. Although I believe the racks design to be a factor in this.
Maybe the manufacturers of cycle racks should be compelled to label them with clear instructions on safely securing a cycle to them?
Anyhow, I believe the stolen cycle to be a Specialized Hardrock Pro. If anyone is offered such a bike in the south east with an odd back wheel (i.e. not an Alex rim and not shod with Specialized rubber) then be sure to reject it. It is clear from the condition of the cassette that the stolen bike had little use.
Or maybe the cycle wasn't stolen at all and the owner of the wheel was literally that. Not the owner of a bike.