"Caitheann an peileadóir an liathróid agus cailleann sé an liathróid."

Translation: The footballer throws the ball and he loses the ball.

[Fingolfin1346]

Bainisteoir: 'What did I tell you about short passing?!'

[Pallethands]

One cannot throw a ball and keep it too.

[SatharnPHL]

If you throw the ball to a team-mate, and your team-mate catches it, you haven't lost the ball. If an opponent intercepts the ball, you have lost the ball.

The verb in this exercise is caill/"lose", not coimeád/"keep".