It looks like if you win on time in under 4 moves then you don't get rating points, which is probably why your opponent timed out before the fourth move.
But maybe that doesn't address your question. Yes, it would be a civil way for the 1700 to leave the tournament if the games are under four moves.
Your rating did not change because the games lastest less than 4 moves. See http://support.chess.com/Knowledgebase/Article/View/16/3/how-do-ratings-work. Note that this doesn't apply to tournament games.
Your 1700 may withdraw from the tournnament after finishing all his games, but before his group has finished all their games. Then other players can proceed to the next round.
I just won 2 games on time in a rated game and my rating did not go up. I am guessing since I didn't really win. I was wondering if the same is true of losing on time. I am in a < 1200 tournament where a 1700 slipped through the cracks. He claims by accident but hasn't left. I figured if he could lose his games without losing rating, it would be a civil way for him to leave.