obstruction rounding third

Question
Runner at second. Batter hits line drive to left. Runner rounds third where third baseman is standing on the bag. Runner bumps third baseman who does not have the ball and it slightly slows runner down. Throw from left to home beats the runner by a mile and even if there had not been obstruction the throw would have clearly beat the runner (by four or five steps) in the umpires opinion. What is the call?

Answer
The call is still obstruction. As soon as the contact happens the umpire will hold out his fist signaling a delayed dead ball. The batter is awarded the base in which he is trying to reach and possibly more if the umpire determines that he would have been able to go further if there was no obstruction.

Just because the left fielder made a good throw doesn't negate the mistake made by the third baseman.