Erm...
I've sat down in coffee bar / restaurant / whatever a million times while waiting for someone, and I always order a drink while waiting.
I don't think I ever responded to the staff that I'll be just sitting and waiting until the other person arrives.
What, they MUST take the first sip of coffee at the exact same second? How about following sips, do they coordinate that too?
Anyway, same shit as always..
When asked by authority figure to do something (in this case, starbucks staff) - you do it
When asked by police to stop - you stop
RLY simple shit.