From Video Description, PSN ID: Wind_Cannon
9:41 is when they appeared to merge, you can clearly see them as one, they stay like this till end of strike.
12:59 is when strike ended, I got the final shot in with 4th Horseman.
13:29 is where you see that the quest wasn't completed.
Destiny: Two For The Road Glitch, quest refused to complete. Shield brothers morphed into one boss, shotgun used was the 4th Horseman, I fired the final shot into it and quest refused to complete, despite having killed both of them, since for some reason, they merged into one thing.
What's going on here? This is just me, I will if I gotta, but I'd really prefer not to have to run strike again.
-
They didn't merge. The first boss does at around the 9:35ish mark. You can see him die when you're waiting to be revived. He probably didn't get killed by a shotgun.