oil pump/Detroit engine failure on 2013 Freightliner - ADVICE NEEDED!

I will try to get the engine codes report and post here. As far as I know, there were no low oil codes. It is unlikely that they could have: 1) started the truck before putting oil in it, 2) putting the wrong type of engine oil, or 3) forgetting to unwrap filters (all of this was suggested as possibilities - thankfully the driver was watching the work, and can ascertain that these types of gross mistakes did not take place. The technician did measure the engine oil four times with a dipstick, according to that shop's policy, and some of this was done in the presence of the driver.

Thanks all for giving some ideas and suggestions, it is definitely very helpful. What sucks is that the engine is not covered by the standard warranty after 2 years, and the oil change place is so far refusing to admit its mistakes. Short of courts, how does one go about such a scenario? How to find out who is the insurance company of that place?

 

couldn't find the Detroit TSB that was referenced here. It looks like they are all here: https://www.automd.com/tsb/detroit-diesel_m/dd15_mm/9999_y/

 

Here's the clarification from the service manager of Freightliner dealership: "The oil pump was not the primary failed part. There is bearing material in the pickup screen and throughout the crankcase. The oil pump locked up as a result of the metal fragments."

"Unfortunately the damage to the oil pump was a result of bearing failure or foreign material that caused bearing failure."

So the question is - if this is not a manufacturer's defect (which it is not), it is not due to harsh environment, and is not the mistake of the driver, how could the oil service station do this damage? Forgetting to dip the filter into oil? Forgetting some metallic part inside somehow? I enclose the image of what fluids, tests the oil change place did to the truck.