Yeah, watched the video ... bus drivers act like they are the most important vehicles on the road and get quite pissy when some other vehicle is in the bus loading zone. He just did what he always does and cut off the autonomous bus and since he did not fully get in front of it the autonomous bus did not sense it in time to stop. My guess is that bus driver is gonna be unemployed soon and new regs will come out for bus drivers that you cannot cut in front of autonomous vehicles.
After thinking about what you wrote, my guess is the bus driver thought “I hate these autonomous vehicles because they are going to steal my job.” Being irate about that, cut him off intentionally — “I’ll show you!”
Yes, bus drivers are very aggressive. They have demanding schedules and they know that that are big and people will back off. So they push their way into traffic and force their way into the next lane over.