Uh... hello? Of COURSE it's an exploit! Compare it to the normal fight. Notice how the normal fight is hard-ish while this not hard at all? Coil is supposed to be the hardest content with complex mechanics, while this is easy peasy with 0 effort from the dps required. If you're just mashing your attack buttons until the boss falls then it's clearly "not working as intended."

I expect them to patch this quickly so that when ADS enrages he actually enrages. Until then, I'll enjoy the easy farming while I can. Of course, I might have enjoyed it a bit longer if the OP didn't just make it public to the ARR team. GOOD JOB! *two sarcastic thumbs up*