I'm no medic. I'm not qualified to deal with life-threatening trauma. And I'm no young fool, full of piss and vinegar, either. I'm sure as Hell not game for a lawsuit as a reward for trying to help you, and botching the job.
And please don't betray an ignorance of how this world works by telling me that a 'Good Samaritan' law will protect me...
No... On second thought, if you believe that, DO speak up. (I've got some property down in Florida that I'd like to show you when the tide's out)
If I see a bad wreck, I'll get on the horn, and I'll call 911. If I haven't got a phone with me, I'll make a call from the next land line I encounter. I'll even spot the quarter if it takes one.
Which beats simply ignoring the situation by a country mile.