The Air Force reported that a pilot ejected from his T-6A Texan II near Vance Air Force Base, Oklahoma.  Based on the report, it seems the aircraft went off the end of the runway (into the mud) and the pilot ejected:

The aircraft is intact, sitting off of the end of the base’s runway 17L, with gear extended in the mud.

The report does not indicate if he was a student or instructor; only that he was solo.  (The term “he” is generic, as the Air Force report carefully avoided the use of gender-specific pronouns.)

Also noted at the Air Force Times.