I really agree. that is also part of the fight, to find spots were the fire wont hit and then stand in that spot for the entire fight, just like kiting Kephess to a corner and LOS him when the big purple circle comes. I don't see how any of them are exploits and I guess Bioware agree with me on this since they havn't fixed it during the last six months... But if you do really think it's a exploit, don't use it and report it to Bioware.
Pretty sure that is how bioware planned it out. I mean behind the walker is the only safe zone from shields it seems like they planned that otherwise why even bother making open space. I've found it curious that a couple people consider it exploiting because the boss can't saturation fire back there. I call that strategy.