Using rear fog lights if a rear bulb has gone

[samwilliams]

About a week or so ago, my right rear light went. Until I could get a bulb (i.e. get home), I decided that it would be sensible to put my one rear fog-light on, as it happens to also be on the right hand side of the car, and could work as a, albeit not perfect, temporary substitute. My main reasoning behind this was that my car isn't that visible at the best of times, and, to me at least, it seems quite important to have a functional light on the rear right hand side of the car.

However, when pulled up at traffic lights, a motorcyclist had a go at me for having my fog light on. I don't actually know whether what I did was 'correct', but I'd be interested to see what other people thought, and what else they would suggest in the circumstances (other than try and carry a spare bulb with me!).

Sam