Listen, it'll never get to that point, as Danny is a smart guy and will just pay the higher amount once he sees the firepower - he'd never allow this to get to the level that Mark states, as then he'd be opening up a whole new can of worms.
The scenario as I see it:
1) Danny finds out about potential legal challenge.
2) Danny relents to higher child support since he does NOT want to let Mark inside his life.
3) Danny lists 30% more hidden-resto books to pay the bills.
To think that he'd let a child support case threaten his source of income is ludicrous, and no matter what you think of Danny, no one can say he's stupid.
I'm not a legal expert by any stretch of the imagination. Whether or not he wants Mark in his life, standing in front of the courts may not be anyone's jurisdiction but the courts and authorities to decide. If there is a child support issue (and from what Mark explains, it is evident that there is one), no investigation can tease out private financial information like a cross-examination under oath. I also understand the livelihood claim you bring up (and how this case can hurt it and the community) but if there is a bursary award in the amount that Mark is suggesting, IMHO the path Mark is taking is logical and well worth the risk.
Don't confuse jc with the facts. Just because some of you are lawyers doesn't mean you have more insight into legal matters than he does.