The "Angel" at the pool of Bethesda

[AaronBDisney]

John 5:4
For an angel went down at a certain season into the pool, and troubled the water: whosoever then first after the troubling of the water stepped in was made whole of whatsoever disease he had.

This is stated as though it is a fact and yet it seems to just be a myth. Or at least I get the idea that it was. An angel troubling water so that the first person in the pool is made whole doesn't seem like God's ordinary method of healing.

If it is, does anyone see anything in the passage that would clue us in that John understood this to be a superstition? I wonder if 'angel' there doesn't mean messenger in the human sense. I wonder if there was some sort of mystic healer that 'came down' now and then to offer healing to the first in the pool. Does anyone know if there's any validity to the statement as it's made in John? Could my proposal have any merit?