Same happened to GoldSearch in Dunolly with a couple of 5k's not too long ago....Indian national with false ID.
Sadly, the police wont help. They say its a civil matter as technically its not theft (the shop handed the detector over willingly under a contract agreement).
Its a breach of contract at best.
To recover costs, you must pursue a civil action against the offender.
Its BS i know, but its what most are finding out today......If you hire detectors, especially cutting edge tech, protect yourself against this happening.
Having said this, if i come across this rat-bag in the field AM, rest assured he will be involved in creating some amusement for the boys whilst we are waiting for the authorities to pick him up.
Cheers