Different times, or maybe not.
Back when I was young, 1975ish, I worked at a busy off licence. Would get Watneys, Courage etc delivering their cans (Party 7!). If we were their last delivery they always had an 'odd extra case' of something available for cash. I learnt a lot in those days also to...
I wonder if one of the boxes has been delivered full of books weighing the same (current Amazon driver trick).
PS, whilst I saw a lot of this, I never participated.
If you were the delivery driver for that load, would you have 'taken a look'?
Or even 'taken a sample'.
Having worked as a multi drop driver many years ago I remember pallets of sweets that were delivered with a few boxes split.