[QUOTE 4056915, member: 45"]As I understand it the lighting regs only apply to lights attached to a bicycle, so you can stick all sorts of flashy/overbright things over your body that don't meet the regs.
That's beside the point here though as the cyclist has nothing attached to their bike.[/QUOTE]
At the risk of starting one of 'those threads', the lighting regulations allow you to attach any manner of light to the front of your bike, so long as it is white, does not flash in an illegal pattern, and does not dazzle. I suspect the same applies to things attached to you, your bag, helmet, etc. So I'm still not sure why this would be sensible, except someone trying to economise or getting caught out.