In most of my playthroughs, I have triggered that cutscene
at the goblin camp, before I met Kith'rak Voss
. This playthrough I have visited the bridge first and triggered the cutscene there.
Could it have anything to do with dismissing / respeccing Shadowheart? Because I think then the artifact automatically goes to me. Sometimes I have triggered her dialogue about the artifact changing ownership by talking to her shortly after, but many times we never had that talk.
Do you remember in which act it occurs? Is it when ending the night at camp, in the morning or at another location?
PS: This playthrough I have rested so much, I stopped getting any cutscenes in Act 1. I guess I got them "all".