Don't scare pedestrians, walk your bike if you must
I always ride on sidewalks to avoid cars. That said, cars to bikes are like bikes to pedestrians. If I see a pedestrian on the sidewalk, especially with a dog, I stop or slow down way before we cross paths. Then I look over my shoulder to see if cars are coming. If not, I bounce onto the road and zip past the pedestrian and hop back onto the sidewalk. If a stream of cars are approaching, I either stop and wait for the cars to pass or if I will inevitably cross paths with the pedestrian I slow down to a walking pace and intermittingly put my right foot down on the ground to pass the pedestrian slowly. I don't dismount and walk my bike because then you're "wider" since you're walking your bike from the side.