I would not want to take a win if I was up 4-3, serving at ad-out, and time expired. I would rather play a single point as you did to decide if you win or tie. In the event of a tie I would also rather play a single point than do a coin flip.
I realize that these aren't the rules though. What often happens is that you attempt to be fair and lose (as you did). Then the next time, you are in the opposite situation and the opponent does not do the same.