I see you are in West Seattle. I used to live there, for 10+ years, and still commute through there/go there frequently. As you know, there's a real lack of bicycle infrastructure in the area. Have you tried explaining why the bicycle commuter would do that filter? If your wife was making a left turn, the cyclist took the safe and reasonable alternative to filter in front likely to get a jump on the traffic behind.

Do you mean he pulled into the "crosswalk" not the "sidewalk?"
And in West Seattle, the intersection you were at most definitely plays a role in the cyclists decision to make that move. There's some intersections at which I queue up and some at which I (legal to do in Seattle BTW, at the cyclists' discretion) filter to the front.
I would not have reacted well to ANY driver making a suggestion for ME while I am riding. I could make MANY suggestions for drivers but you think they would take the comments well? Not likely.

...My ex-husband was a road-rager and at times I refused to ride in the car with him - he made ME feel unsafe many times. At least he never did it to a cyclist. I think he knew that would be a very, very bad idea.