Wasn’t Penn also the primary operator about a decade back with the long running scheme to inflate payouts on small track horse races un-regulated ?
People would bet relatively large bets (like $5k) at track on small races where the typical handle would be sub 10k - playing the long shots. This would cause the pari-mutual payouts to shift wildly and faves would have payout of like $4-6 on show bets because of the artificially inflated wagering pool. Smart people were pumping up the pools like this and when the normally heavy chalk fave won - they would cash in having bet $25-50k un-regulated and taking advantage of the artificially high return.
Tracks of course saw this - but they turned a blind eye. Everyone was happy - the operator had a higher handle, clerks and horsemen were in on it and betting alongside the fixers. And un-regulated had worse controls than legal casinos and were too busy raking in the sucker money for a decade to bother looking at why their racebook sucked so horribly profit wise.