I don’t like saying it but that CFI is in for an unpleasant experience with the FAA.
Training records, logbooks, compliance with Part 61 (or 141) pre solo training requirements.
How many times was this student taught power on stall recovery, elevator trim stall, bounced landing recovery etc etc etc.
Maybe the seat unlocked as a result of the bounce and he slid back.
Thats kind of what it looks like.
I feel sorry for both of them.
Thats not fun to be going through.