I wonder what the cost would be to have an automated system that sends an SMS to the registered phone number five minutes before SAR expires. Same for beacon activations; just a message saying "the ELT in your plane/boat has been activated, can you please check and call us on xx-xxxx-xxxx if it's a false alarm?"
It seems like that would solve 99% of the accidental false alarms, leaving more time to concentrate on either true alarms or deliberate false alarms (can't do much about the latter).