So first issue on top of the mind is Crota seems to get dropped and then stand up right away as a sword hits him. The issues where Crota will be half way up and not fully standing and suddenly lunges at the sword carrier. These are really difficult bugs that pretty much force a wipe. Yes each time the sword carrier was at Crota the moment he fell. So something is up.
Then there is the occasional permanent invisable wall that appears heading towards way to Ir Yut and Crota. Yes the Shriekers were killed and enemies were at this point gone.