Fireflower Amulet interaction in a party.

I'm running a lightning spear amazon and my partner is running a fire build chronomancer using the Fireflower Amulet. While in a party when my lightning spear passes through her flame wall it's triggering the effect of fireflower on me and causing me to die instantly when hitting a large group of enemies.

There is nothing on the amulets description that suggests it should be triggering for allies.
Is this an intentional interaction or a bug? as it's making mapping in a party with her impossible for me.