Hey folks, I spoke to designers Toby McCall and Jesse Sky and this is what they had to say about this:
When Nightmare Mode was released, Overload had no activation time, but its ballistic component was not working (which meant Overload could be completely ignored). We corrected this in the patch. In Nightmare Mode, the optimal path will always appear on either the left or the right wall, so a wall will always be available for tanking the demolitions probes.
So the intended change is to no longer make this boss a "puzzle" boss. There's no more reason to try and find a solution.
Seriously? Plus, as the previous poster pointed out, if it's "either left or right" what guarantees that we will know at the beginning and not halfway through the minefield when it's too late to turn back? If the solution is "if left is green at first square, then it's left, if right is green at first square, it's right" then that would be doable... however, if you an't tell which path to take from the very beginning... then this is just stupid. Basically picking the wrong door w/out any hint as to which way to pick would be a stupid mechanic. I seriously hope you guys put that much thought into it...