Did Dima hide his serves at the WTGF

In his Rnd. of 16 match against Koki Niwa, it seems that Dima hid a few of his pendulum serves with his free hand.

While he usually tucks in that left arm chicken-wing style, a few times he seemed let it linger. Here's what I mean. I'm not saying they won him the match, as he is in impeccable form anyway. It's just that I count maybe 3 instances of it where he is not called on it.

I'm a Dima fan myself, and I'm all for giving him the benefit of the doubt--sometimes I forget to pull the arm away on a high toss serve too--but at his level, three times is a lot.

What are your thoughts?

Hi Leeman,

Yes it certainly looks like in that serve his arm is still in the way.  Players are still not perfect with this by any means.

I think it is difficult for the umpire to be watching this especially if he is only doing it sometimes.  I think it goes back to the problem with the rule.  It is difficult to enforce.