Federer hit the ball “with negligent disregard for the consequences." It is clear from the footage that he doesn't look where he has hit the ball and that it hits the ball boy. It could easily have hit the ball boy in the throat. According to the authorities in the Djokovic case it is not where the ball hit the lines-person that was key, it was the “negligent disregard for the consequences." The same “negligent disregard for the consequences" shown by Federer.
According to the rules he should have been disqualified.
dude, do you live in real life?
imagine that you are driving the car.
imagine that you are speeding. If there is no radar, or policeman - you've done a wrong thing, but there will be no consequence
imagine that a radar catches you. You will receive a fine.
imagine that as you are speeding, you come to a road cross, and the traffic light changes to red, but you can't stop in due time, so you keep driving. And there is police. You'll be screwed in many countries.
imagine that as you are speeding, you come to a road cross, and the traffic light changes to red, but you can't stop in due time, so you keep driving and an accident happens, but the damage is only to the cars. You'll be screwed big time.
imagine that as you are speeding, you come to a road cross, and the traffic light changes to red, but you can't stop in due time, so you keep driving and an accident happens and there are serious consequences for some person, up to death. What do you think will happen to you?
imagine that as you are speeding, you come to a road cross, and the traffic light changes to red, but you can't stop in due time, so you keep driving and an accident happens and there are serious consequences for some person, up to death. When the police makes a blood test, they find residuals of weed for exampl. What do you think will happen to you?
Perhaps in all instances you didn't mean, and you didn't want to cause any damage, so even less was your intention to cause serious health consequences, or kill someone.
Perhaps you were only looking to get some fun, in the wrong place.
Perhaps that was your way to let some steam out.
Perhaps you are a really nice person.
But the punishment will depend on the outcome, not on your intention.
Are you sure that you still don't see the difference?