sorry the question makes no sense
nothing can make an objective wrong into an objective right
there may be circumstances that mitigate or remove individual guilt for the wrong action, but it is still objectively wrong, and no matter how good the outcome the individual intends in doing the wrong action, that still cannot make it right.
I read the soccer story and sorry, still don’t see the grave wrong involved. What am I missing? what is your question? If the soccer coach is behaving in ways that endanger children or break rules of the league, report him to the authorities and let them handle it, that is their job.
The OP is being overly scrupulous. He believes he knows of a lie (the boy must buy the socks but another parent bought them against this arbitrary and worthless rule) so his conscience is bothering him as to whether he tells the truth or not on how the boy got the new socks demanded. He should forget it, for a number of reasons. The rule on the socks is arbitrary and unfair and he must forget what he knows about the socks because he’s the driver for the kids – not a parent.
What knowlege he has came about in some indirect way and he’s not responsible for any of this, so he must put it out of his mind. If he were a parent, and if he were in the U.S, we could advise him on how to proceed against the coach. But, he’s not asking to take action against the coach but, rather, whether he has an obligation to report that the boy did not get the socks on his own and another family bought the socks contrary to a stupid rule. We have no obligation to support stupidity and it would create greater harm to the boy if this ridiculous coach found out his stupid sock rule was violated. If it were my son, there would be no more soccer but this man is only the driver for the boys. Possibly someone more familiar with European soccer league structure could chime in, but I do not think he’s in a position to take this above the coach since he’s not one of the parents, unless he had the backing of the parents too who don’t seem to be proactive against this coach.
Are you in Germany or Austria? I have to ask because though I realize how important soccer is to Europeans, it belies belief that parents put up with an abusive and archaic coach. It would be much more helpful if someone knew who was also from the same country, but you create no sin by keeping quiet. Just do the driving, for now.
The parents need to get together and do something about this coach, even to leaving the team or league. Here in the U.S. this would not go on because the coach does not own the team and there are ways to remove an abusive coach or parent. But that’s not the question.
OP, you need to also speak with a priest on a tendency to be overscrupulous – seeing sin where not telling the truth (about the socks) would protect a child from an arbitrary coach. The coach has no right to determine where the boy’s socks come from, so you have nothing to do with this.