Double boss spawning (Izual on Nightmare)

[Deleted]

Hi,

So I think I've discovered a bug where I spam-skipped a cut scene about in the time the boss spawned in it and as a result, one of him stood there talking and the other one charged me and atacked (in the cut-scene and remained for the fight).

Here's a video:

Unfortunately I didn't capture the part where it starts.

It didn't feel like anything that can be exploited because the timing was so particular, so I feel like it can be posted to the public .

Edit:
Also, does anybody know how to disable friends being able to just join like in the video?