OP...based on the description you gave, you were in the right, and dipstick in the car was wrong.
You were going straight, and he was turning. He had a stop sign and you did not. Ergo, you had the right of way, and the fact that he had started but had to stop due to a pedestrian speaks volumes about his driving skills in the first place.
__________________
1 bronze, 0 silver, 1 gold