Sawblades are one of those mechanics where melee can be targeted but only under exceptional circumstances. We've had our DK in melee range, get targeted by a sawblade, because there were no viable ranged targets (alive/on platform). Even I was alive and I wasn't chosen for it over him.
We've never had a melee targeted with lasers, but it's probably the same case. You shouldn't worry about it, since if all ranged are dead it's a wipe, or maybe a last man standing kill.
They do tend to build in safety nets to ensure you don't bring 2 MWs and all melee dps to a fight just to completely negate 50% of the mechanics.
Edit: Hm, though that doesn't explain st33l's situation! Maybe it's positional, then, like desecrated weapon.