As far as I can tell much of this story is based on someone claiming to have seen remains of a baby in a septic tank. A lot of this is just sensationalism. The mortality rate at the home would be less than the whole of Ireland at the time.
Why they were buried in the field and did they properly register the deaths is the question.
The Bon Secours sisters (the nuns who ran the place) apparently provided the death records for all of the 796 children - but not the burial records - as in location(s) for where all the 796 are buried at.
If not for both, then why not for both?
The “Septic tank” was a memorial, with headstone and marker. All the deaths were properly registered; that’s were the “800” number comes from; there were apparently far, far fewer buried in the mass memorial. Laissez-faire is insinuating that because the story doesn’t SAY there were burial records, we might as well guess that there weren’t.