I don't think the roll is OP at all. In fact, I used to be a scamper WHORE. I play both Scoundrel AND Operative (along with 3 other classes at 55, and more lowbies).
It is my favorite class, and I have to admit there's a reason everyone wants a Scoundrel / Operative healer. It's NOT because of the roll. They have the strongest single target heals. End of story. Call that OP if you want. Maybe it is. Maybe Mandos and Mercs need a healing buff to get on par with Scoundrels... I dunno, never healed on those as I can't stand the play style.
Lastly, Scoundrel and Operatives have trash defensives. The roll is all they have (aside from Dodge which is used as a cleanse, and whatever the other one is,) and its easily countered. If an Op uses their roll while they are slowed, and keep spamming it as a getaway, they have burned all of their energy. Sure, they might have Cool Head off cool down, but this is a terrible way to play. Instead, you should be running toward your meele DPS and hope they peel off of you... Sometimes LoS, or however the situation unfolds.
If you really want to talk about them being OP and give legit reasoning, you should be complaining that they are the #1 healer in Arenas, and no serious team will ever want to bring a Mando or Sage. That is the only real argument I can see. #1 single target heals.