This is going to drop like a stone.
Most British greyhound racing stadiums use an outside mechanical hare. The hare comes round the track, passes the traps, the traps open, the dogs emerge and chase the hare. The race finishes and the hare stops. Then some greyhounds savage the hare in a desultory manner, disappointed with the lack of meat to be had on a mechanical hare.
About 20 years ago, and probably earlier, my local track operated such a hare. I distinctly recall people there (bookmakers, trainers, punters, etc.) referring to this device as an Outside McPherson. I can’t find any reference on the internet.
Has anyone here ever heard of this appellation?