We were called by an exam moderator to say that they couldn't read the USB drive of drama performances we had sent them.  No problem, we'll send you a replacement, says I.  Look everywhere for the files, can't find them.  Ask the Head of Drama, can't find them either.  Perform a mini-investigation and all we can establish is that the performance had happened several months earlier, recorded on a camcorder subsequently returned to us with no instructions to save the contents, and the files were nowhere on our network or any laptop involved in the transfer.  The camcorder SD card had been erased and re-used.

These are GCSE performances involving several students.  Erk!

Asked the examiner to return the USB drive as a last straw.  When it arrives, plug it in and get the message "this drive is empty and needs formatting".

Erk again!

Bring out the big tools - EaseUS USB recovery, get it to scan the drive which takes about an hour.  Offers the three missing files and asks if I want them reconstructed - do I ever!  Let it chunter away for an age and it says "files recovered".  Test play them and the video works perfectly!  Copy them to a new USB, and also to the network drive, give it to the Exams Officer and let the Drama teacher know.

Mucho brownie points.