Looks to me like the bus changed lanes (in front of the black truck) and the white car tried to follow behind the bus not seeing the truck. Beginning of the video bus in center lane, then right lane, truck in right lane, white car in center.
the white car was behind he bus- not in front of the bus where he couldn’t see what was behind the bus- the white car with the black truck right beside the white car=- how could they not have seen it?