Whether it's OK or not I don't get what is so vitally important that you cannot wait 10 minutes more whilst the aircraft taxis to the gate to make a call.
I'll always remember a passenger who kept standing up during taxi to the gate and was asked several times to sit back down. Aircraft had to stop suddenly, he went flying face first into the seat across the aisle, leaving him with a rather nasty cut lip and lost tooth. No one needed to say anything, the shock any embarassment on his face said it all. Then we all had to wait whilst he was seen to....