"No, he doesn't need an ambulance..."

I was leaving the library and pedalling through the Memorial Park in which it sits when a teen crossing the grass  from the other side of the footbridge fell over. He didn't get up.
I changed direction pretty smartly. I recognised him. He has epilepsy. I had never seen him have a seizure before but he had once mentioned it in the course of telling me why he doesn't ride a bike. 
It was very obvious to me what was happening. I have seen many, many epileptic seizures in my time. I once had five children with epilepsy in one of my classes. I have seen more than one of them rushed off in an ambulance.
I reached him and, with great difficulty, managed to push him over so his face was not in the grass. 
At that point someone else rushed up and said, "I'll call the ambulance!"
"He doesn't need an ambulance," I told her, " He's having a seizure. He'll be okay in a minute or so."
"He might need CPR!"
"He won't. He's fine. He's coming round now."
Her hand hovered over her phone. I was hoping she wouldn't call the ambulance. If he wanted help he was going to be able to tell me in a moment.
He went on lying there for a moment giving those odd little jerks which are the second stage of a seizure and then blinked. He looked at me and then saw the phone in the other woman's hand.
"No ambulance," he told her rather abruptly if still a little groggily.
She put it away reluctantly and then, with a disgusted look at both of us, strode off muttering things about people who "don't want help when it is offered".
He looked at me. My words must have registered with him even though he had not answered at the time.
"Thanks."
"You're welcome. Want any more help?"
"Just let me get to that seat. I'll call my mum."
I waited while he did it and, when she had answered, I left him sitting there quietly waiting for her. 
He didn't need me hanging around. He's a teenager. He needs his independence.
There are times when an ambulance is needed. He didn't need an ambulance. He wasn't being deliberately rude. He didn't want a fuss. He really, really didn't need an ambulance.
I hope the would be good Samaritan understood that.