What, a landman withdrew an “offer” - shocker! Understand that the oil and gas land “discipline” is, if I may lovingly say so, fraught with the ‘shoot first, ask questions later’ syndrome. The single greatest thing mineral owners can do for themselves is to know what they own and are contractually bound to - and have the “receipts” to back it up. If you’re not confident of this (and so many are not), hire professional help who has a fiduciary duty to you and you alone.
Anyone can challenge anything they’d like to. The question is whether it makes sense to do so. This is of course where all the facts and details come into play. Do some back of the envelope math to figure out the possible benefits. Variables will include: number of net mineral acres involved, old lease royalty rate vs the going rate now, RRC records (the root source), local and regional geology and/or drilling-permitting activity, and who you’d be up against. You’ll want a specialized attorney who’s done this many may times - and has the history to prove it. Think about a fee structure that makes sense. Don’t get involved in these % of whatever type deals. Hold your nose and pay them by the hour, with a fixed fee bonus assuming success (as defined by you).
You cannot generalize this type situation. Way too many important variables are at play. While it will make for interesting reading when/if others chime in here on actual experiences, your set of facts and characters involved are yours alone.