Today at the World Cup, Poland learned an important lesson: always, always, always pay attention to where everybody is. Otherwise, you might end up looking really silly, and also losing a crucial World Cup game.

Let’s break that nonsense down. Just after the hour mark, Senegal’s M’Baye Niang went down with an injury. Poland, a goal down at the time, decided not to do the customary thing of kicking the ball out. Eventually play was stopped after an enterprising Senegalese player kicked a nearby Pole.

Niang was treated and went off, as the rules require. He then stood by the edge of the pitch waiting for the referee to wave him back on, as the rules require. And Poland, bless them, decided that while he’s off the pitch, he’s somebody else’s problem. That’s not in the rules. It’s not even in the guidelines.

So Poland, pressing forward, sent a header up into the opposition half. At this point, the referee sees Niang waiting and waves him back on. He trots onto the field at around the halfway line, just as the ball comes back and Grzegorz Krychowiak, blissfully unaware of Niang’s presence, decides to send a looping backpass towards his goalkeeper.

Cue panic.

The central defender turns and realizes “Hang on, where he did he come from?” Poland’s goalkeeper Wojciech Szczęsny decides “This calls for me to run out towards the ball as fast as possible.” The defender leaves it for the goalie, and the goalie is far too late. Because Niang, by some distance the calmest man on the pitch, has got to the ball first and poked it past Szczęsny. Now he just has to roll it into an empty net, then try not to laugh. He manages both.

Two lessons here. One, just because a player is on the other side of the whitewashed line doesn’t mean they have ceased to exist. And, two, when somebody goes down injured, maybe kick the ball out? Even if they’re faking, good manners cost nothing. Karma is real, and sometimes it’s very quick.