Doom upon all the world achievement glitch (Spoiler)

There's a similar error for the dragonslayer trophy whereby if you're controlling a follower instead of your main character at the instant the 10th dragon dies, the trophy doesnt pop, but does if you reload, refight and switch back in time.

In light of that, by any chance were you controlling one of your followers (say, vivienne) when the final cut scene chain begins at the end of phase 3 of the boss fight ?