While working at the law firm (well, both my parents' law firm, and my dad's friend's law firm), I've had to fill in on reception from time to time, and at BOTH places, I was allowed to go to the bathroom or get a drink/snack from the kitchen without telling anyone. I guess the rationale was, people won't die if they don't get through THAT MINUTE, and even if they did, they wouldn't have any guarantee of getting through to a lawyer. My dad's partner just LOVES to stomp around and heave and sigh about how busy and indispensable he is, and put his phone on "do not disturb" for hours at a time. At one point, it got so bad that I actually had to walk up to his office and tell him, "Mr. Britishdude, the Whatsits are here to see you."; and this was a SCHEDULED CLIENT VISIT that he'd known about in advance.