Not one person, so far, has commented about the man arguing when asked not to use the term 'sweet'.
All he needed to say was "Okay, sorry."
From the link given by Blossoming -
The price for whatever has been purchased usually comes to a note – usually £10. The householder disappears to get this – this is when the scam begins, according to the police. When the note is handed over, the lad examines the condition and how long it took the person to get it. If it is crumpled, they accept it and move on. If it is crisp flat and new – they are much more interested and may engage the person in more conversation, to obtain details about them. As they leave they will smell the note. If it is slightly musty – this is an indication that there is more in the property. Those addresses are noted. The addresses of elderly / vulnerable / gullible people are all noted.
Whatever they call you, watch out!