>>534956697
Maybe he had unmatched zeal picked? There was another guy a while back who also thought that vanguard has to be doing the executions to heal others by 30%. But it's a team perk, so you need to execute extremis yourself for you to heal.
The UI prompts in this game really need to be reworked. Most of the time they're either misleading, incomplete or outright false. Don't they have someone to verify this stuff, hell modders corrected most texts.

Also:
>nig playing vanguard
I don't believe in coincidences but this made me chuckle.