Eder is using a shield that has retaliation (retaliate against melee attacks). I used Kana's field triage skill to heal him up a bit, and Eder retaliated against Kana. I can't imagine this is intended behavior (this was outside of combat, no other effects active to cause the problem other than their modal abilities).

Hey Outlandish,

 

This is not intended behavior. I've put this bug into our system and we will work on a fix for an upcoming update.

 

Thanks for the information

This bug is in the current live build as well.  And doesn't only apply to field triage.  Things like lay on hands is also affected.  I'm guess it's any targeted healing.  My guess is that the check for retaliation is if there is a change (regardless of negative or positive) in stamina, and whether change was affected by someone within melee range.