Most buffs don't trigger assist aggro?

[Tecmos Deception]

A lowbie warrior was killing a few orcs in EC just now on green, and I hit him with talisman, guardian, strength, chloro, and alacrity while he was fighting. None of the orcs he killed ended up giving me a faction hit, despite my buffs landing on him while he was standing there slicing them up.

As a test, I fired off a minor heal as the last orc was fleeing, and that did trigger the faction hits for me.

Did those buffs not put me on the aggro list for those orcs AT ALL? As in, if they had killed this guy, they would have just walked away without coming after me? Even though I buffed the shit out of him (tali especially surprised me since it basically is a 200-point heal in addition to just the 200-point max hp buff) while he was IN combat?

Is this intended?