Any idea why this lawsuit is being brought now, almost two years after the tragedy? Maybe the surviving family was so traumatized, it took them this long to become clearheaded and organized enough to do all the paperwork and contact the right lawyer. That would certainly be understandable.
I think you answered your own question. Maybe add the virus factor, which has been emergent since shortly after the incident. Hard to imagine the impact this had on the family.
Er, did you not notice the recent pandemic that caused courts and law offices to be closed for months?
On top of that, there was probably quite a while spent grieving, demanding answers and then attempting to be ‘nice’ by asking them to pay compensation for their gross incompetence. The pace of government (adjusted for the pandemic) would account for this as well - perhaps they got the run around and only recently got the “FOAD” reply from the government.