Having driven both school bus and tractor trailer (Farm kid) and also was a police officer before I went back to college again. My point of view. If you watch that video the 8 way system on the school bus wasn’t activated. So the bus driver never had his yellow lights flashing before he stopped. Which means the red lights just came on no warning when he stopped. Making it hard for the truck driver.
That being said the truck driver was not paying attention at all though either. HE should have noticed the bus slowing down. Also you never pass on the right hand side. Especially with a bus. I’m pretty sure the Stae Patrol will take away his CDL over this. IT’s probably taking awhile to charge him do to the fact that the state will have to decide what all to charge him with.