Why paper? I'd expect the docs would go from the word processing software printed directly to pdf. Then the pdf would be uploaded. Generally, government agencies and courts accept ONLY pdf documents.
Now, I don't know if this is relevant - While some here have said that only adobe has a pdf engine, that's not true. There are others, including open source. Some of these will handle complex or unusual formatting differently.
But I will admit, the errors look like OCR errors. Assuming it was a collaborative effort, I'm not sure how the OCR came into play. Perhaps members of the team were using different software - Word for some, an Apple program for others, etc. At the last minute they may have tried to pull them together, but the conversions were not going well, so they used OCR to bring text from one document to another - copy the text you want to use, then run that through an OCR machine. I do that from time to time - I'll use OCR on some electronic text when I am trying to bring it into one of my docs. No paper is involved.
They may have taken it out of current versions, but my old Microsoft Office Word will save directly to PDF. Or, as you suggested, you can print to PDF.
“Why paper?”
So Sandy Burglar can stuff them in his shorts, of course.
As I said, the mechanics of the legal profession change slowly, but there are arguments for having a physical copy. It can’t be hacked, for one thing. It creates a paper trail for documents and their history.
Most likely the documents were prepared electronically, printed, and then faxed somewhere, the faxes were scanned into a PDF and filed electronically, with the paper to follow during normal business hours. The people that are prepping docs are not in their home offices and the courts are not open 24 hours. Some of those steps are unnecessary - the print-scan step seems superfluous - but on the other hand, look what happened to the documents relating to Hunter’s laptop that were shipped with (allegedly) no backup. They were swiped en route. Electronic and paper redundancy can matter. And maybe there are security issues involved in the electronic filing, like a VPN connection that is only allowed from certain locations. Most lawyers are not particularly computer savvy, no more than most, and their paralegals are also not typically computer science majors or IT experts.
Anyway, no matter if the documents are prepared electronically, there is ALWAYS a paper backup.
And you are correct, there are numerous PDF engines. Adobe no longer has a monopoly on reading or writing that format. That’s been true for a good, long while, now.
It absolutely was a group project, directed by the lawyers, but the construction of the final filing was done by paras. After that there would have been several iterations of proofs and corrections. And you can see that some portions were boilerplate with square brackets around fields to be populated. (That’s what we were doing 20+ years ago, creating templates with fields to be populated. Square brackets and all. Then stringing them together according to what ever legal/business rules applied and populating the fields.) Most of the document is original work, but the initial parts are standard legal templates. I would bet a decent sum that the initial work was done in Word and it didn’t end up as a PDF until somewhere close to the point where it was filed. Those square brackets are artifacts of Word mail-merge fields (which don’t have to be used for just mail merges).