Did you read my reply, in which I said that I specifically tested the aggro behavior of all of the EBs and found that they obeyed standard aggro mechanics when they were Taunted, another entity built up more aggro, the door clicker left them in the dust and another player character was in aggro range, or they were attacked after losing target on the original door clicker? They obeyed the expected aggro rules in every case. If they were Taunted, they stopped attacking my character and attacked the Taunter. If my character was out-damaged, they aggroed on whatever was dealing more damage to them. If they stopped chasing a door clicker because they couldn't catch him/her, they aggroed on the next available character (mine). If I attacked an EB which someone else left behind in a click and run, it broke off pursuit and aggroed on my character.
I didn't read something on the forums and assume it to be true, I tested this. Extensively. I know that they can be aggroed by something other than the character which clicked the door, despite your assertion to the contrary, because I spent time testing how they interacted with my characters after reading that they ignored pets in another thread. That comment piqued my interest and pushed me to investigate whether it was a problem with pets in general, specific pets, or a problem with the aggro mechanics, or player expectations. I found that PA immediately and irrevocably Taunted the EBs away from my Ill/TA controller. I found that the Robotics henches could pull aggro off of my mastermind as long as I wasn't using attacks, sticking to buffing/debuffing/healing the robots instead. I also found that Singularity could not pull aggro, with either the controller or dominator I used, and that made sense, as the pet has no Taunt and low damage. Having exhausted the list of pet-based characters available to me, I moved on to testing how the EBs responded to my other characters. I had several EBs stop chasing other player characters and attack my Shield/Elec tank, my Ice/Stone brute, my Street/Shield scrapper and my Kinetic/Willpower scrapper when they loped through my PBAoE toggle radius, in PI and in Kallisti Wharf. I attacked EBs which I saw running past and successfully aggroed them, with a variety of archetypes at levels ranging from 34 to 50+. In every case, the initial aggro sent them to the door clicker, but all of the aggro mechanics which should have shifted their attention away from that character functioned as expected.
I also tested Placate with my Night Widow, and found that it worked as expected, and Misdirection with my Dark/Martial dominator and that also worked. So clearly, the aggro mechanics were properly functioning for that type of Threat manipulation. What I did not do is Placate and walk away, or wait for them to despawn, but based on all of my other test results, I have no reason to expect that they would not aggro onto anyone happening past or attacking them, as that's what happened to my characters several times. If they remained permanently aggro-free after a Placate, even when a condition warranted aggro (you attack again, another player ventures near enough to aggro the critter after the Placate duration expires, another player attacks, a pet attacks), that would be a bug.
Nor do I accept your insistence that any of the behavior I witnessed is "an issue". If these EBs were coded to be laser-focused on the door clicker and ignore all aggro mechanics, they'd make short work of every mastermind, even through Bodyguard mode, especially that damned mummy; Illusion controllers would be fucked so hard and fast that they'd never go near a door again; and everyone without Barrier or at the level minimum for them to spawn would've been on the forums, making the "ZOMG U NEFFED FARMS" bitching look like warm, fuzzy group hugs, to highlight a few examples of the repercussions of such a design. Regardless of what you presume after looking at the string @Faultline posted, or even what @Faultline himself said, the HC team would not design critters which excluded player participation if they weren't on the "right" archetype or using the "right" powers or at the "right" level. That's just not how they do things.