Takeaway Coffee

I expect I sound funny when I try my French and Spanish abroad but sometimes it is hard to get to grips with foreign accents in your own locality.I bought a coffee to take away this morning in a well known high street coffee shop. The conversation that followed my purchase went like this.
'You want a lead for that Sir?' I was asked
'A lead?'
'Yes, Sir, a lead.'
'Why would I want a lead? Is it dangerous?' I asked.
'Dangerous? No, Sir. Not dangerous. Fresh ground coffee from beans. No chemicals. No chemicals at all.'
'Why would I want a lead then, if it is not dangerous. I mean I want to drink it now, not walk it!'
'But you said you do want to walk it Sir...take away. Is why I ask if you want lead. If you want to drink in now, lead is not necessary.'
I was getting confused
'I want to take it out...with me...on the street... now,' I said.
'Then you should have lead, Sir.'
'Well if it needs a lead,' I said, 'it definitely sounds dangerous.
'Not dangerous, Sir. It fresh. Hand made by barristers.'
'Barristers? Your coffee is made by barristers?'
'Yes, Sir. Very good barristers. They have two week training.'
'Two weeks? I thought it took years to be a barrister. That is very quick! I wouldn't be happy using them for a legal case.'
'No. No Sir. No legal case needed. Coffee is good. No suing. But you must take lead if you want to walk it.'
By now I just wanted my coffee and was even more confused. I decided that I would take whatever lead the guy had to offer and be on my way.
'Ok, I will have a lead, thank you,' I said.
He handed me a lid. A lid for the takeaway container.
'Oh...a lid!' I said, the surprise showing on my face.
'Yes Sir. That's what I say. A lead so you don't spill coffee. You might sue us if you burn yourself.
'Well, I suppose so, but if you have your own barristers then they must be used to defending any claims you get,' I said, trying to make light of the situation as I felt my cheeks redden at the thought that he may think I had been taking the mickey out of his accent.
'No, Sir. They just make the coffee. Not do suing case.'
'Strange barristers then, that don't do legal work. Must be expensive for the....'
It was then that I saw the leaflet and the line 'hand made by baristas.'
Having appeared foolish enough already I resisted clarifying my understanding with my foreign friend, jammed the lid on my coffee container and bid him good morning.