As I said .... to my mind this is not a spectator sport.
I can see no reason for 20/30,000 people being there.

It's the onlookers that have created such problems not the Travellers.

I also oppose cruelty but am realistic enough to realise that it happens - occasionally accidentally (as in this case).

I'm sure that having spent money on buying the horse the last thing the owner intended to do was to drown it. Whereas in the case of racehorses etc. the owners accept death as a possibility when they place their animals in such situations.