From what I read, there is a little blame to go around, with the exception of the helper who was permanently injured. No blame can be fixed to him, as he was only a helper without knowledge of UPS policies and procedures.
The driver has a lot of blame, simply because he either was too stupid to stop doing his job and tell his supervisors that he would no longer drive until a replacement vehicle was brought out to him, OR, he was intimidated by management threats to finish his job. Hey people, alarm systems are there for a reason. No amount of intimidation should ever make you forgo an alarm system on your vehicle. I could care less if that means your load will not get delivered. The load is besides the point. Remember? Safety first? I'm only going by what I've read on that web site, but I would pin 25% of the blame on the driver.
Then, 75% of the blame rests with UPS. Bottom line, if the equipment is faulty, it lies with them. They are the ones who spend all of this money on efficiency, then any problems within that system needs to be ironed out by UPS. The supervisor who brought out earplugs will, and should be fired post-haste. We go through this topic frequently on this forum. If safety is first, then safety is first. PERIOD. UPS can kiss the front and back side of my brown pants if they want to complain about it. Loads come secondary to safety. Now we all know when the pressure is on, management will do everything in their power to make you forget about safety to get the job done. Obviously, if a supervisor comes out and brings earplugs when a safety buzzer is blazing, then they don't want to make the proper corrections. This is not to be unexpected with this company. But ultimately, the driver should have handed the sup the keys and told him he wasn't going any further until this package car was repaired or replaced.
Now when I say 75% of the blame goes to UPS, that includes the mechanic that signed off the DVIR that, "the vehicle is OK to operate". I don't know of too many mechanics that would sign off like that without direction from a mechanic supervisor directing them to do so.
Again, I'm only going on what I've read, and some things seem to be left out. They said the truck wouldn't start, then the next sentence says they were rolling down the hill without power. Something is left out between those two statements. So I'm only writing about what I know here. I admit I don't have the whole story. And nothing was said of what possible injuries the driver suffered. Nearly everything mentioned was about the helper.
Having said that, the two most important things I take from this are, ONE, if you are a driver, and something on your truck is wrong, get it fixed before you continue. PERIOD. I don't care what kind of crap management tells you. Particularly if it is safety related. No amount of intimidation is worth getting injured for. And only you can prevent it. If it doesn't sound or feel right, chances are, you're right. Call in and get it corrected however it needs to be done. And TWO, safety is merely a buzzword at UPS. They will spend millions of dollars on safety programs and training, but where the rubber meets the road, getting the job done is their ONLY priority. Anyone who has worked here for any amount of time knows this.
Bottom line: take care of yourself because no one else will.