Is it possible he hit one of the F keys and booted into a recovery mode by accident?
It's possible - depends what recovery options the oem put on there.
Is there anyway to recover the files from the formatted disc or is he SOL?
You should be able to get some back - as long as they haven't been overwritten .
The Free Recuva (they do a portable version you can run off a flash - or run it from an external machine to avoid writing anything else to the HD ) is worth a try.
It has a deep scan mode for formatted drives.
Pandora is also a decent freebie - good for certain types of iles - see screenie in link below.
Paid apps. might be beter still. Easeus Data Recovery Wizard is also worth a go. Recover Files After Format