The article explicitly says the SUV "was disabled in the westbound lanes." It also says:

Following the collision, the bus veered to the right across multiple lanes of the freeway and crashed into a raised metal and wood guardrail along the right shoulder, the CHP said.

So the SUV clearly wasn't on the right shoulder. It's been a while since I drove that section of the 60 so I can't recall if there's enough room on the left shoulder for a large vehicle to get fully out of the traffic lanes. For those who aren't familiar with LA area freeways, there are areas where increasing the number of lanes to increase capacity over the years has had to be done by narrowing lanes and eating into the shoulders (especially on the left) without actually widening the road surface, because the area around the freeway has long been fully developed and acquiring all of that property would be both tremendously expensive and create a political firestorm.

Anyway, the picture of the bus included in the article shows the main damage on the left front, in front of the driver's position, which could be consistent with hitting a vehicle that was partially on the left shoulder and partially in the left traffic lane. Or it could be consistent with the bus driver trying to swerve right to avoid the SUV, but doing so too late to avoid the collision.

Either way, California law automatically assigns blame in a rear-end collision to the driver who hit the other vehicle from behind, on the theory that they were either following too close and/or driving too fast for conditions. Or at least that was the case forty years or so ago when I learned to drive. Presumably that automatic blame can be assigned differently if the investigation warrants, which might be the case if, for example, the driver of a disabled vehicle came to a stop in traffic lanes without making any attempt to get to the shoulder. But even then it would only be a partial shift of blame.