Depends on how shaken you were. Such a calamity happening to your home would put some people into a mental shock where clear thinking wasn't first and foremost.
I'm sure the police probably dropped a few balls on compiling these records, too. It was an unprecedented calamity.
Maybe some people didn’t know they are supposed to “check in” with police, or such was the last thing on their minds?
I recall hearing many owners of condos there were foreign visitors, who visited just at certain times of year. Maybe such people were listed as missing, but were in their home countries, and again, didn’t know that they were supposed to check in with police.