Normally, once the laserer hits steel (or hits nothing, due to the beam going outside of the level or reaching its maximum range), the laserer will revert to a walker a few frames later.
This might work fine with one-way arrows, but I don't remember specifically coding for it, so this needs to be checked.
I can say for sure that the laserer cannot destroy wrong way one-way arrows. I recall testing this 100%. It's simply a question of "will the revert-to-walker kick in properly?"
Okay, confirmed, no bug here - it works as it should.