In a pub, why would somebody prefer to drink coke from a can than a glass?!
Answers:
Germs maybe, yes they might be clean but they might have a phobia
or
they may want to be mobile and want to walk outside and so want something they can take with them like the can
or
even they may be weight conscious and want to read the Label to know their Daily intake or sugar, carbs etc.
only thing i can think of is maybe he likes the taste of the coke in a can, since coke from the syrup/CO2 mix can be adjusted to have more syrup or less depending on the place. also low syrup, or mixxed tastes from multiple other sources(coke/mt dew/sprite/tea/water all on same dispensing gun)
OK so get a coke can and get a glass of ice pour some coke in the glass and taste it now compare it to the one in the can it has a different taste and can drinks r better
Believe it or not, some people prefer the "can taste".
I think the man doesn't want to wait just for you to get the glass
when its in the can, it has more taste then in a glass