Thinking in that way it is entirely true, for example in Mayberry mod I've seen calls to heart attack in front of the hospital.Well, any medical call in the woods themselves would be similar to a SnR call, as trees should make it hard to pinpoint the victim's location. Although it will still be called out as a medical call. Masking one kind of med call as a "missing person" wouldn't work, either, as med calls happen to random civilians around the map, and missing person in front of a hospital would look strange
As for making a separate new freeplay event without missionscript - that is considered hard, I believe.
At the Erie Co. fair they use basically that to transport a patient to a "Aid Station" before being transported to the hospital.Statue of Liberty has some "unique" equipment and procedures, I do love their dorky little rig though, its so cute