The quickest way for Haley's arm to mend?

[Porthos]

Vampires get a +8 racial bonus to Listen checks, and Durkon has a very high Wisdom score. That adds up to overhearing Tarquin's insane rants through the deck of the the airship.

Or someone popped below decks and told him Haley needed her arm fixed and he better prepare Regenerate along with Restoration.