Oooh, that is some bad advice. You cannot lie to the police that you’ve been carjacked when you have not been. The police will investigate and charge the suspects based on what actually happened and if your story is different than what happened you can get in trouble for lying to the police.
Ultimately, what I would like to see is a system similar to how Ring cameras now provide you the ability to give permission to police to tap into your street-facing Ring camera. So, let’s say something of yours is stolen then if you communicated with the authorities and they indicate that they are going to take action then you can provide them with some kind of code which if they use as credentialed law enforcement, would cause a couple of things to happen… you would (unfortunately) lose your ability to track the AirTag but, they would gain the ability to track your AirTag, and crucially, Apple would stop any stalking notifications on that AirTag. Seems to me a system like this would strike a reasonable balance of safety and security, while not alerting the criminals that they are being tracked.