Crack! I was just moving off from the lights when, with a sharp noise, my foot slipped and something fell from the bike. Fortunately, it wasn't me. Unfortunately, it was the r/h pedal. The body had broken away leaving the spindle in the crank. Roadworks at the junction combined with quiet traffic meant being stranded in the middle of the B4469 wasn't anywhere near as traumatic as it could have been, and I only had about two miles to walk home. Unfortunately, this means I only got two miles riding.
Looking at the pedal now, there are small cracks and chips in the inner surface of the sleeve, for want of a better word, that forms part of the pedal body and goes round the spindle itself. I'm not sure if this is what caused the failure or is a result of the failure. It also looks as if something might have either snapped (very cleanly) or simply unscrewed itself at the end of the spindle where it fits into a bolt on the outside of the pedal body. I hadn't noticed any looseness previously. They were cheap pedals but only 18 months old. Genetic brand. Came from SJS – I'll see how they respond to an email.