As i was turning final he gave a rolling call for an intersection departure rwy 19! So there i was, rolling out on final to see a King Air starting his roll.
Once the King Air is outside the gable markers for RWY 01 he's no longer on RWY 01. If it started rolling from the intersection of RWY 01 / 19 while you were in the turn to final (ie not established on final), then he was probably actually outside the limits of RWY 01 by the time you finished turning and were established final and therefore you were OK to land.
I may not have been good etiquette, but its not clear to me that it was actually against the rules.