“YWN reported that the child at the water park wasn’t noticed to be missing until the kids returned to their busses.”
I see nothing of the sort on this site Misaskim reports they were still poolside and saw him in the water. Claiming they were on the buses gives a false sense of negligence (as in your last retelling of facts) which breeds motzei Shem rah. Perhaps it is inadvertent , in which case I apologize.