"It's my right..."

I was told yesterday. 
As soon as I heard that I knew I wasn't going to win any argument with the person who said it. It was not a good day.
He is a familiar figure around the shopping centre. He was standing right next to where I had (legally) parked my trike and he was smoking. 
There is a smoker's "bin" about  ten metres away. It is, quite deliberately, where people who do smoke won't impinge on the rights of those who do not smoke.
     "You reformed smokers are all the same..."
Hold on, I have never even tried to smoke - but I say nothing.
He went on and on as I packed things into the trike basket and tried to get around him.
     "You aren't going anywhere until I've finished..."
He told me this and deliberately blew cigarette smoke into my face. I could not get around him to unlock the trike from the railing. I knew I would not be going anywhere until he decided I could. Someone else was coming up the ramp that leads into the shopping centre. 
     "You all right?" he asked me rather warily.
     "I just need to unlock," I told him, "I'll be fine."
He just stood there. Neither man moved. I didn't want a fight to break out and I know the smoker might react that way.
A couple came up the ramp. They stopped for a moment and then hurried in. People came out through the sliding doors that lead into the centre and hastily went on. 
And then one of the local care hostel staff came out.
    "Hello Cat... T....bothering you?"
    "I just need to get going," I told her.
    "T.... and I need to get going too. T... can you carry these for me please?"
She handed over two supermarket bags. He took them with a volley of fine Anglo-Saxon words and started off.
    "Sorry Cat. He got away while I was waiting for the meat."
    "Will you be okay?" I asked, "I can ride back with you if you like?"
She hesitated and then shook her head,
     "No. He's done as I asked. We should be all right."
This man is mentally ill, seriously mentally ill. Most of the time he is docile enough but there are times when he does get violent. When that happens they try to keep him contained but it is difficult. I watched her walk off rapidly - before he stepped out into the traffic without looking in either direction.
What a responsibility.