Useless lecture

I live in a dangerous town for bikers. In less than a week I witnessed two incidents that could have been tragic. Unlike last time when the biker ran a red light, today, it was the car driver's fault. A large red SUV at the center of the intersection with its blinkers on to indicate a left turn. The cyclist was coming right ahead but the driver just turned. Forcing his way (in truth, I don't know if it was indeed a "he". It could easily have been a "she") and cutting right in front of the bike.
The biker veered quickly off course and recovered nicely but he was clearly upset and turned his bike around. He went chasing after the SUV which was stopped at the traffic light at the next intersection. I saw him pulling next to the red car, knocking on the window. I could not hear anything that he said but he didn't seem too upset. Probably just lecturing the driver on the importance to check that the road is clear before turning in front of incoming traffic. I'm not sure the driver ever opened the window. The light turned green and the car sped up. The biker came back slowly. I saw him shrugging a couple of times.