Most modern EMRs will flag results like this. If it happened to arrive in the middle of the night like the author said, the PCP would have just been asleep. I don’t think there are systems for waking up PCPs for concerning lab results.
Having someone on-call to deal with routine lab results that just happen to catch a possible imminent threat would be an enormous waste of resources.
So now you need an extra on-call doctor just to filter out the false positives, or the on-call doctor gets notification fatigue and ignores them.
Or in the best case you send a lot of people to ER in the middle of the night for no reason. Again thanks to liability concerns, but this time on the part of the primary care practice.
Or a PA or CRN. They are cheaper. As the last resort you can have an AI doing it :-)