you know 🤔 ... now that you say that I don't think this is a passivation issue. this is probably exactly what happened. he wasn't extracting the metal dust and it acted as a polishing compound.
I bet that dark spot is polished, not oily.
looks like an oily spot to me, I agree with a few others. you need to passivate. If that turns out to be what fixes it, I would be talking to the manager or owner about at minimum a partial refund if they refused to learn about this before taking on the job.
I always laugh when I see a comment section filled with "hurr durrrrr my miata could do that"
the level of precision control this truck has on extreme surfaces is astounding. most people have no idea.
I ended up picking up the 30 in STANLEY FATMAX FUBAR to keep in my underseat storage for emergency egress. You have to be careful where/how you store stuff like this in your cabin, since everything becomes a missile during rollover or hard crash.
since we have an up-armored truck, I keep this in my underseat storage for emergency egress. I'm not asking my truck permission to exit, I'm informing it of a guarantee:
probably not going to be deemed a total loss by insurance, but I bet it will come close to be honest. If they do total it, negotiate a buyback from insurance and fix the truck with money you get from the payout.
big pro tip: make absolutely sure you file a diminished value and loss of use claim...