As Canadian Break and a few others have said that once the decision to go to an alert status is confirmed, it has to be followed through to it's pre-arranged conclusion - even if all 'appears' to back to normal.
Who knows what is really happening at the other end of that mic, or what duress is being put on a person(s) on board to either do or say the right things...
If you have or have access to high value assets or are key holders, some domestic alarm monitoring services will still initiate an on site visit to confirm you don't have a gun held to your head - even after confirming the cancellation password if the sequence of alarm triggers indicate possible intruders. With an airliner ....
It makes sense to me.