When you put it that way.
I think it is pretty whacky how quickly the cast channels. The best way to counter it is to always expect it I guess. I’m sure you can find a WA to track it if you wanted to (not certain on that though). Best thing you can do is try to stay in line of sight of your healer and around pillars unless you absolutely can’t. Also of course, interrupt the channel as soon as possible, or use any kind of CC to stop it. And hope your partner is watching for it too.