I am not an attorney, nor do I know of a case where a non licensed person transmitted on licensed amateur frequencies with an emergency. I'm not saying someone has not done that, I just am not aware of an incident or the legal ramifications if any.
What I can tell you is that I am a licensed amateur radio operator. If I am out of range of cellular service and have an emergency, using an amateur radio would not be first on my list. Using a PLB (Personal Locator Beacon) and or an Iridium messaging device like a Garmin Inreach product would be first. It could be hit or miss on getting into a repeater and that is if someone is monitoring and is able to accurately note my information and pass that along to emergency services. Honestly, if I need to provide someone first aid I am going to be busy doing that. No problem pushing a button on a device and then getting back to the first aid. I have no time to fool around with hoping to reach a competent person on an amateur radio repeater or via simplex.
Before hiking with friends, whether they hold a license or not, I show them how to use the beacon devices as I may be the one who needs help and I don't want them ****ing around with a damn radio.
Still, if I hear someone on the radio saying they have an emergency, the last thing I am going to be concerned with is asking their call sign. Also, an emergency to me is human life or limb and maybe property.