More likely it was the Polar Vortex that hit May 9th, 2020, although health issues may have prevented Cliff from saving damaged trees.
The late freeze in April 2007 was the worst ever recorded in middle TN. It killed nearly everything I had to the ground, EXCEPT for the kaki persimmons and Rosseyanka, grafted on local wild persimmon. They were not tricked by the early warmth, and were still completely dormant and unfazed. However, I think a freeze in May would have done them in for sure.