Well, in theory, that is a treatment. But reason and execution are wrong, in this case. The safety pin airway, you pin the tongue to the lower lip w/ a cotton ball, or etc., to keep the tongue from blocking the airway. Also have to be sure they don't drown in their own blood. This would be something you'd see in like a remote or wilderness accident, where you have no other airway tools, no access to EMS, and your patient is unconscious and doesn't have a patent airway. Should you do this? Probably not. It's easier to keep a $2 OPA kit in the first aid kit. But it is explained in several popular survival and wilderness medical guides.
As for the OP. Go for it, get trained as an EMT, or a First Responder, give it a try. That's how a lot of people get into EMS, having an up close experience just like you had. It's safe to say that you can't really be prepared for everything, we're not always mentally ready. The general public, I expect to be out of sorts after an accident or a medical emergency, especially, the person who witnesses it first hand. One of our jobs, once arrived, is to not only handle the situation with the victim, but calm the bystanders. There's nothing easy about EMS, but it's a lot fun, and sometimes it really sucks. A person never knows how they will do, until they get out and get their feet wet.