The FSOA doesn't exist in lore/canon?

Followup from my previous post regarding this topic.

Kerapac is still wielding the Staff of Armadyl in Extinction, which can't be possible if the player took it from him before then, which also means that its examine text - "The fractured and unstable Staff of Armadyl, taken during Kerapac's reign of terror." - is entirely non-canon, casting doubt on the veracity of examine texts in general.