I have a 55 operative healer, and last night found myself getting destroyed in HM Hammer station at the tunneling droid. I was focusing on the tank, healing and cleansing, but no matter what the probe droids kept coming out blowing up around me. This caused me to have to run around for a bit trying to survive and the tank died because he had too many stacks. Now I have gone through this FP before, and never had any issues, never drew any aggro. After the wipe, the tank suggested that I wasn't geared well enough, I responded back that I can't heal and cleanse while I am getting hammered. I am not sure it was the tank's fault, he kept aggro well on the boss. I think the DPS weren't focusing hard enough on the droids.
Hmm, sounds like you were running around way more than necessary. Every time I have run it, as tank, dps, and healer, we ignore those droids. They don't actually attack directly, they just move close to someone, turn red, and explode a few seconds later. So stand still until they turn red, and then move only as much as you have to to get clear.
As an operative, be sure to keep your HoTs running on the tank, including Kolto Infusion. I know a lot of scoundrels/operatives forget about that skill since it costs both a stack and energy, but the HoT is pretty powerful, and will usually give you the stack back before it expires. You are also by far the most mobile healer, since you can reapply your other 2 hots, cleanse, and hit Surgical Probe on the move.
So with the info you gave, I'd have to side with the tank here. Not sure if it is a gearing issue, or if you just panicked when the droids came by and you lost focus on healing, but I suspect the latter.
Not sure what your play style is, but good practice for an operative is healing between pulls while running. In pretty much every PuG, there is at least one person that refuses to self-heal between pulls. Healing them with HoTs, instant heals, and even cleanse, while we are all running to the next fight helps me get comfortable with healing on the move. It also ensures I have full stacks before the next fight begins.