That's the point. Radek argued that he wasn't challenging. Isner absentmindedly hit the ball long thinking it was a challenge, and then Radek said he wasn't challenging, and he should get the point cuz the Isner's ball went out.. Such bush league it's almost incomprehensible he's a grown man. So Liyani, said fine, you don't want to challenge, then you lose the point for hindrance. Raising your hand, your racquet, is no doubt, without dispute, the international sign for a challenge and has been for the last five years. He stood their with his racquet above his head. Just despicable.