Swords in Crota's End affecting Challenges

So by now we all know that after killing Ir Yut in challenge mode, the one who used the sword, can't be swordbearer for Crota or challenge will fail(unless you wipe).

Yesterday, with my Warlock we went all the way to Crota, no wipes, I killed Ir Yut, 2 others who didn't touch the sword killed him and we didn't get the challenge, turns out that the game(I'm assuming) counted the swords from the Bridge.

Unfortunately I forgot to take a picture because we were just focused on getting it done. Then on my Hunter run, almost the same thing happened, I killed Ir Yut, 2 others were going to swordbear, Crota killed us on the first try and look at the "swords used" in the death screen: http://imgur.com/a/8bJTG.

Can someone confirm that this is indeed true or if it's a glitch or whatever?