Captain - Romulan
From: Starter Set (IRW Khazara)

Q) When firing on a Borg ship that has Borg Ablative Hull Armor equipped, does Toreth's ability to convert a hit to a crit still work?

A) Yes. Rulebook Page 13: "If the attacker and defender both have abilities that modify attack dice, the defender resolves all of their abilities before the attacker resolves any." So the Borg Armor would covert all Crits to Hits and then Toreth would convert 1 Hit to a Crit.