This encounter comes down to the RNG of him delaying his cast times slightly so they’re kickable within a 15s CD window. WW monk doesn’t have a pet to soak and letting this cast go off is nearly always a wipe. See this video, scroll to the final ~ 20 seconds.
https://vimeo.com/manage/videos/728492309
Both leg sweep and paralysis are on CD since they’re necessary to interrupt the double worm casts.