Specifically, it is the Heart of Sabik at the core of the weapon that the Allag scholars failed to truly comprehend. If you take a look at the shape of the Weapon, clearly only some of it is raw Allag tech; the outer armor is unmistakeably Garlean - the horns and chest piece are modeled after the armor of Gaius himself. Perhaps the Allag scholars were guilty of the same hubris -they saw the power of the heart and decided, "Yeah, that'll do. Rig it up." Perhaps this isn't the first time the Ascians have gotten involved with the technology. Mysteries in mysteries... I've yet to find anything else on it, though.