I would ask a fellow farmer who also happens to be a Jewish Debt Collector if this is a common practice in the Debt Collection industry, but this is one of those rare instances where I don't think that intersection actually exists.
I am not, but I do have some professional experience as an attorney in an adjacent field and general awareness of how the legal industry operates.
First let me say from the onset that the bar for debt collection attorneys on the whole is a lot lower than the average attorney. These attorneys typically work on a flat fee basis, meaning instead of billing per hour, they are paid a flat sum. As a result, these attorneys are incentivized to process as much as possible as fast as possible and the field rewards those who prioritize quantity over quality. Debt collection for attorneys generally involves reusing and duplicating the same materials over and over again with the specific names and amounts substituted, so the need for actual legal experience is far less than other types of work. Because of this, a paralegal theoretically could handle most of the "grunt" work related to collection of debt provided the form letter adheres to applicable law, even though they're technically not supposed to practice law. Because the system rewards quantity above all else, less scrupulous lawyers will be cutting corners to maximize income per hour and going beyond cutting corners like Joe here by pawning off the assignment to office staff.
In an ideal world, one would hope that an attorney reviews everything that his or her name appears on. In practice, it unfortunately can be very common that the attorney performs basically zero oversight and trusts the paralegal or other office staff to process routine work under his or her letterhead. For these attorneys, having a solid form letter serves to cover your ass, but it can only save you if you're using the form letter correctly.
Here, Joe fucked up on several levels according to Plaintiff. First, Joe's staff used a form subpoena to serve an out-of-state debtor, which is not permitted under New York law. Second, it was sent by regular mail, instead of in the same manner as a summons. Third, the date it proposed to schedule to deposition was December 26, a federal holiday. Fourth, it was not timely because it did not provide 10 days' notice before the scheduled deposition date. Finally, it did not have the statutorily required language. Joe admits he fucked up at least to date of the deposition and the service of process.
All of this reeks of inexperience and lack of oversight. Some people have stated that Joe did this intentionally, which I myself find hard to believe, especially since he was not carrying malpractice insurance (an absolutely insane prospect, by the way) and the risk-to-benefit analysis is horribly skewed (why open yourself to multiple potentially six-figure lawsuits merely to collect four-figures of pocket change debt?). Further, people speculate that there may be many unknown potential FDCPA claims against Joe lingering out there, but I would bet that most of Joe's collection business would have been intra-state and therefore not have the same issues as this matter. Not to say that there aren't other potential claims against him out there, just that I would not suspect there to be that many all things considered.