I hadn’t seen anything about something that far south, either (that I recall) but having multiple parts of the same object arrive at slightly different times appears to be more common than the reverse. We should all wait to see about the dating of this new find — perhaps it happened earlier or later, like perhaps it’s dated the same as Berringer crater(still no solid, agreed-upon date for that impact).
From a VERY long COMPANION ARTICLE it seems the group which includes Firestone, Kennett et al have settled on ~12,900 years ago. No mention of their dating method that I could find.
Now Berringer is a whole 'nother story. I haven't read anything anywhere(haven't really looked) about their dating method. Many moons ago???