911 is reporter shorthand; a PLB does not call 911; it sends a signal which notifies SAR and they come looking for you. A SPOT is different, it is run through one of the SatPhone companies who then contacts SAR, kind of like the way alarm companies work.

911 gets a lot of abuse from people calling to complain about service at fast food restaurants and other BS. Sometimes 911 operators ignore emergencies too, just because they don't believe the person on the phone. Some of the more egregious examples have gotten widespread publicity when the end result was someone dying because the operator didn't believe the person or didn't care.

The first person to use a PLB was arrested the second time he used it when he went back for his gear after the first rescue and set it off again claiming he was too tired to hike out with his gear.