I suppose my issue, then, is that 'the same channel' already cannot be used to counter-attack unless the target has the ability to do so independently, and that if they do independently possess such ability, there is no reason inherent in the power as written why they should not be able to do so
To put this in perspective:
Me shooting at (attacking) you with a gun does not grant you the ability to return fire despite not having a gun of your own, but if you do have a gun, it doesn't stop you from doing so, either (unless I change from attacking to placing an offensive block...but then I'm not attacking)