I was mistaken, it is not a problem in roUrlTransfer. It happens when I pass an HLS maifest URL to an instance of roVideoPlayer
There's a few layers of abstraction, but the implementation is nothing more than this:
m.screen.contentList[0].Stream.url = url
m.screen.Play()
If the URL fails to respond (at least I
think that's what triggers this), I get a flood of OnHttpError callbacks from the video player.