I doubt they are at liberty to say anything at this stage in view of possible legal moves.

To be fair to them the only "warning" seems to have been someone saying the local hunt taking over the nearby farm constituted a risk. While I personally think hunt supporters are not who I'd want my daughter to marry I don't think EH could put the henges on an at risk list for that reason. ;) So far as we know this was an unpredictable event and they can't be blamed.

Not like seeing people misbehave at solstice year after year and doing nothing about it!

More to the point, I wonder if this land was under a DEFRA stewardship scheme? Most farms are nowadays. I wouldn't like to think I was paying someone so much a hectare to look after the archaeology here....

NB I haven't suggested who might be responsible for the damage, not wanting to be sued. It could be a case of a mistake committed by a contractor. Who knows?