Although the rules governing international judo competitions only require that both combatants, after their matches, bow to each other in the traditional salute of the discipline, these days they often shake hands.
Unless, of course, one of them is the Egyptian Islam El Shehaby and the other one is a competitor from Israel. El Shehaby displayed the reaction many Middle Eastern athletes seem to have, but only when the Olympics requires them to be in proximity to or display basic respect for an Israeli athlete: Pure boorishness.
El Shehaby lost the bout and then doubled his filing status under the "l" word by having to be called back to the mat to bow to Israeli Or Sasson. He then went for the hat trick by refusing to meet Sasson's outstretched hand. The crowd at Rio, who had been schooled in basic decency, booed him immediately.
The International Olympic Committee opened a disciplinary commission that will meet afer the games are over and decide what, if anything, to do to El Shehaby. It's hard to say what the result will be. On the one hand, the IOC has demonstrated it doesn't much care if Israeli athletes get a little shabby treatment, nor is it overly concerned with the Games' overall history as it regards Israeli athletes. And they have the out that the sport's own rules don't require a handshake. But on the other hand, they could make themselves look decisive and tough by telling him he's been a bad boy. And since he already lost his way out of the tournament, that wouldn't really matter.
A gesture that looks tough but means nothing. That's one event where the IOC is unlikely to ever finish out of the medal round.