Warwick Ult + Challenging Smite goes through Tryndamere Ult

So, just saw this in-game, whenever warwick ult and challenging smite was used on tryndamere, he'd die during it even if his ult was up, though, it did occur once when challenging smite was on trynd and i didn't have my ult up, but he still died with his Undying Rage up. If anyone could test this quickly on their own time, that'd be great, since I Cannot at the moment, though I will try to test it in a custom game tomorrow