One of the sticking points in the NFL CBA is that the owners refuse to open their books. They claim they need to claw back some of the monetary gains made by the players in the last CBA because teams are not "profitable." Apparently, the players are just supposed to take their word for it and give back the money.
The players union, not being stupid*, is not going for it. They have consistently asked for financial information. The League has responded by offering to provide aggregate numbers with no data or documentation to back up the numbers.
Again, the players, not being stupid, are demanding the actual numbers so their own accountant can review everything. The owners are still balking.
In a child support case, one can't just say what one's income is. One must produce documentation in the form of pay stubs and bank statements. If one fails to produce this information there is big trouble. It must be produced under oath too (at least in Maryland). Which means if you lie, you can be criminally charged with perjury.
This is for everyone. Your average folks who have some savings, the big rich folks with multiple houses, and the folks living paycheck to paycheck. Even those receiving state assistance must produce verified proof of benefits.
Yet, the NFL in a major negotiation with the players to work out the new financial agreement (among other things) for the future of a multi billion dollar industry, want the NFLPA to just take their word for it? Not happening. If the player's union sues, they will have to produce a lot more in court. If they don't they will face a lot more trouble from the judge than a simple "produce the stuff, please" that happens in most family law cases. They could be facing huge monetary sanctions. It certainly will influence any final ruling.
It is better to disclose up front, than be forced to disclose. The court always hates the side that tries to hide information.
*At least not stupid on this issue. They may be acting stupidly in other areas. The owners may also be acting stupidly in other areas too, while smart in others. The scream you may hear at 11:59 ET tonight will be me if there is a work stoppage.