This has been called "pseudo science " in the past (the idea of a comet breaking up and hitting earth, causing the Younger Dryas Ice Age) and a lot of the proponets who had proof over the lat 100 years or so were pilloried for making such a "wild" accusation, yet there were so many facts available. There is a link to the paper above this, in case you do not want to go through the web page.

DOI: 10.5281/zenodo.400780