If someone walked through your office treating coffee with such little care, they'd have Super-Soaker'd the entire HR department with piping hot lattes to the eyes. If you saw a stranger behaving like this with a cup of coffee, I bet you'd intervene.
There are other times when a character will take their very first sip of the "coffee" and slap the cup down on the table, at which point it'll make the hollow pop of an empty cup. This is such a noticeable issue that a writer at Slate seems to be as consumed with it as I am, and has been keeping track of the worst offenders.
It's time for Hollywood to start putting some liquid in their cups. That way, when a Gilmore Girl whose personality is mostly based around a love of coffee decides to get a cup of her preferred Joe, she isn't suddenly breaking the laws of fluid dynamics.