Equestrian statues

Yesterday I came across the following in a magazine I was reading:

If a statue of a person on a horse has both of the horse's front legs in the air, the person died in battle.  If the horse has one front leg in the air the person died as a result of wounds received in battle.  If the horse has all four legs on the ground, the person died of natural causes.

I posted it here without really thinking about it but soon received a response stating that it was an urban myth. 

That did set me thinking and of course the statue of William III in Clifton Street in Belfast does not accord with the 'rule'.  Neither indeed does it apply to the equestrian statue of William III in Bristol.  William died in 1702 from pneumonia after a riding accident and yet in both cases he horse has one leg raised.

Whether or not it was ever a rule for equestrian statues at some period in the distant past or in some country or culture, I do not know.  However it is clear that that around the world today there is no correlation between the horse's legs and the manner of death of the rider.