Even the well-studied Chicxulub crater has had its radiometric date
changed more than once.
What has happened to the U/Pb-in-zircons date of 64.98 +- 0.05 Ma that's
mentioned in Night Comes to the Cretaceous? (Especially considering the fact
that the latest dates for the K-Pg boundary are half a Ma older -- but this
seems to be a common discrepancy between U/Pb-in-zircons and K/Ar, Ar/Ar and
the like... ~:-| )