Well, not entirely accurate. If the Ashman starts and attacks a lineman that Generates a Counter Attack (rolls an armor), the Lineman will get the Counter Attack, and if the Lineman kills the Ashman (without Generating an Overpower) the Ashman's Act With Certainty would trigger, so they would make their melee attack, which if it triggered a counter attack, that attack could strike a different active lineman, which could cause a cascading affect.
Now, if instead, the Ashman attacks the lineman, again triggering Counter attack (rolls an Armor), and in response the lineman rolls a parry (which would normally trigger the Asman's Counter Attack) the Ashman would not get the Counter Attack, since he can only use this attack against an active unit. Since the Ashman is the active unit, he has no target that he can hit (counter attacks only target active units, while Act With Certainty does not have the "Active Unit" restriction)