I've been listening to Randall's Kosmographia podcast Younger Dryas episodes. In the multiple episodes he lays out research supporting and detracting from the YD impact hypothesis. When they discuss the Hiawatha impact crater it is regarded as a possibility but not a sure thing with correlation to YD being reserved until more evidence is found. From what I have heard Randall is more of a credible independent scientist than he is given credit for. There is very little jumping to conclusions and always demanding evidence to support hypotheses.

He said, if it were 12000 years old, that would be a massive clue for the Hancock's theories. Well… it's a little bit older. Not what they hoped for.