Unfortunately a child was hit because the cyclist is an asshole and so is the duh of the kid. So, of course it escalated because the two adults are really just children in adult bodies.
The cyclists where I live can be the biggest bully assholes. They have their own bicycle lane and still try to monopolize the sidewalks.
I had a cyclist try to ram me off the sidewalk (yes, there was a bicycle lane right next to it) because I refused to give him the entire sidewalk. I called his bluff and grabbed his bicycle by the steering wheel as he passed and pushed him out of the way. At the time I was working on one arm pull ups, so I was very strong but not obviously muscular. I remember how kids bullied each other and I also remember exactly what to do when a bicyclist tries to bully me. A riskier technique is to put the heel of your shoe against the spokes of their bike and they will lose control and go flying but you have to watch out for a flying person and bike.
There is a decent amount of asshole men out there who will bully women at any opportunity if they think they can get away with it. They aren't so fast to bully men because they may punch them or retaliate. I think it is important (when reasonable) that women make it very clear they aren't going to tolerate this crap.