SK passive healer mercs can pull agro

So I've /bugged this a few times in game to no avail so might as well post this here. I am not sure if this happens outside of this one mission I've been doing but it isn't a rare occurrence inside this mission. Specifically the 19th Anniversary "A Formal Dinner Party" mission. I roll in there with a SK, a ranger, and a shammy. All three running mercs. shammy tank, ranger healer perma passive mostly and SK with a healer merc. While doing pulls with the SK in there on occasion the healer merc will get smoked when I FD even though it was on passive prior to me even starting the pull and when it gets revived it is still on passive. This is hella annoying as it wastes plat and time. Not super common but not rare either. I ran that mission twice yesterday and it happened twice.

This isn't me forgetting to put him on passive and he sneaks a heal in before I go FD. I literally mean he is passive before I even start the pull and he still gets killed. This also never affects either the ranger or shammy mercs who are also passive during the SK pulls. Only the SK's healer merc has this happen.

I saw this a few times on my monk when is was heavy farming Fight Fire. All mercs on passive, for a good bit, but would still cast a single heal for no reason and get splattered.

Doesn't formal dinner party have one of those aggro modifier things where you pull them they aggro the whole group, or else is it getting smoked because of some AE a mob is casting? I remember something with the damage/aggro being heavy and troublesome.

The only mobs I saw that were linked were the ballroom dancers and where I've seen it the most is clearing the library not the ballroom. The library doesn't have any agro linked mobs and no it wasn't some AE killing the merc. I could FD without either of us taking damage and it was obvious the mobs turned and beat the merc to death.

Something like this happened to me on my SK a few months ago in Tempest Temple in TDS. SK was alone not-in-group, with a healer mercenary. Before aggroing anything, healer mercenary had cast buffs. Specifically, Greater Protection of Vie Rk. II which is a melee damage rune with a heal-on-fade due to damage hit amount expiration.

Mercenary was passive, I ran through mobs on SK and train train train FDed. The melee damage rune expired before FD due to the mob hits using up all the damage counters.

The heal component of the the rune expiration was probably attributed to the (passive) healer mercenary who cast the original buff, so all the mobs ganged up on the healer mercenary while the SK was FD.

Note spell description:

Spell: Greater Protection of Vie Rk. II

Places the protection of Vie on your target, absorbing 10% of incoming melee damage. This spell absorbs 78997 points of damage before dissipating, healing its bearer for 7284 hit points when it breaks. If the protection is not all used by 1:12:00, it will dissipate without healing the bearer.

This part - healing its bearer for 7284 hit points when it breaks - is my guess as to why the passive no-aggro mercenary was targetted by the mobs after FD.

Good theory!

The Vie heal is cast by SPA 333 (Doom Rune Consumed). SPA 333 is used on many self (or pet) buffs, but I don't find other examples of it being part of a targeted buff. It's possible that caster accreditation is bugged because it would not be noticed except for clerics (or pet casters with healing AA).

This is easy to confirm by having a real level 88+ cleric cast e.g. Rampart of Vie on a FD capable character who: takes enough damage from an NPC to trigger the heal, and then feigns death. If the NPC attacks the cleric, then we have our answer.

A pet caster can also confirm by noticing if the heal is focused and critical heals because of their own gear and AA. If either is true, then the pet owner is the caster of SPA 333. Since the pet has none of those abilities the heal should always be for base value if the pet was the accredited caster. Again this can go unnoticed wrt hate assignment because of the situation. For classes who can FD their pet (and themselves), they might have seen this issue too.