I've ran into this issue many times with the nexus and archon priest. I can't say that I did any damage to the boss in the final 30 seconds but that shouldn't screw me out of the bounty if I'm doing crowd control during that time.
English
-
From what I've personally witnessed and completed myself, as long as you've landed at least one hit on the boss, you claim rewards. I even noticed this earlier today while I was finishing leveling a new guardian. I was in an area where there were wolves were present, even tho I can collect Queens bounties, I was 'unable' to inflict damage to the 'Wolf Boss' as I was getting '??' However I popped a few shots their way anyway. I didn't realise until there was about 30 secs left but I still had an ether key! Missed the chest tho lol. Just saying this kinda backs up what I'm saying above..
-
My issues with the nexus and archon priest have been going on since I started Destiny about a month after initial launch.