Found a tape that the TMC shows to be ACTIVE, and ISMF shows as scratch. Tape was scratched and then immediately reused.
They had installed 2 methods for TMSCLEAN to notify OAM/ISMF of a tape being scrathed. In TMOOPTxx they had ROBSCR set to YES and SCRTCH set to YES. They had also put in TMSXITS with code to do the notify. This set of options caused TMSCLEAN to call TMSXITS and do the notify to OAM, and ROBSCR to do the notify. The 2 notifies were done far enough apart that another job mounted the tape between the 2 notifies causing the TMC to say the tape was ACTIVE/PRIVATE and ISMF to say it was SCRATCH.