I think what I can do on a "push" is follow up with a "dummy" event in which everyone who wagered on a push can just pick the "dummy payoff" and wager what they did on the push
then I'll settle the dummy event and can return everyone's wagers
a bit of an honor system will be in force
so if you bet 100 on an event and "pushed"
look for the follow up dummy event and wager on "dummy payoff" for 100
then I'll make the dummy payoff the winner
you would "win" 100 thus getting your push wager back
and then you get back your dummy 100 as you "won"