Calling a serve let in the middle of a point

Hi Alois,

In the currently ongoing WTTC 2014 tournament, I saw a point in the match between (I believe quarter finals) Timo Boll (Germany) vs Chun Ting Wong (Hongkong), where Chun Ting was serving and after two or three exchanges Timo pointed out it was a let. Do the rules allow players to do this so late in the point, if the umpire has not seen the ball touching the net? 

The point is played at around 13:36 if you watch the video on the ITTF website.

Hi Abhinav,

The players will decide between themselves that it was a let even if the umpire hasn’t seen it and they will slow down till the umpire calls it.  I think there is a lot of goodwill between the players to allow this to happen.

That is what happens in this situation.  They both realise it is a let.  Chun Ting plays one ball and then realises that it was a let and Boll has also seen it.  The umpire does the right thing in my opinion in calling a let.