The National Park service says it was crossing a road when it was spotted by the driver of a camper who jammed on the brakes, only to have a motorcyclist ram into the camper.
If you're on a motorbike, behind a camper van that's braking heavily, and you on your much lighter and shorter braking vehicle still hit it... I don't think the Tarantula is to blame.
I'm not sure about motorhomes specifically, but cars brake faster than motorcycles can.
Motorcycles being lighter + half as many contact points give them significantly less friction. Breaking too hard will pretty easily cause a skid(or abs to engage)
If your vehicle needs more space to come to a stop, don't follow the vehicle in front of you by less than that space.
If you rear end someone because they emergency breaked (for any reason, good or bad), it's almost always your fault. Exceptions for if your breaks fail in that moment or if someone else rear ends you into the vehicle in front of you.
Added benefits of not following so closely on a motorcycle: less exhaust in your face, more distance from rocks lifted by tires, more time to assess and act on surprises ahead, less likely to be rear ended yourself because you can stop slower.
Maybe, you weren't there. For all we know there's a new breed of super tarantula mutants secretly evolving in Death Valley. Soon, we'll start hearing reports of cities destroyed in the Southwest by battles between Godzilla and giant spiders.