Correct incorrect outcome

The only way to do this is to manually edit the database to change specific fields in 3 different tables to put it back to the state the event was in during the "Awaiting Settlement". Also, you will have to manually take back any money paid out to anyone that shouldn't have won anything (this needs to be handled through the cash/points system that you are using)

Manual Steps.

Table: xf_nflj_sportsbook_event | edit the row for the event and modify the following fields:
event_status [set to awaiting_settlement]
date_settle [set to 0]
amount_paidout [set to 0.00]

Table: xf_nflj_sportsbook_outcome | edit each row that has the event_id for the event you want to roll back and modify the following fields:
outcome_pays [set to N]
amount_paidout [set to 0.00]
outcome_settled [set to N]
outcome_date_settled [set to 0]

Table: xf_nflj_sportsbook_wager | edit each row that has the event_id for the event you want to roll back and modify the following fields:
wager_date_settled [set to 0]
wager_amount_won [set to 0.00]
wager_settled [set to N]

What I'd do is run through it at least once on your test site before attempting on production. Create a dummy event with a couple outcomes, place a few bets and then settle the event. Once that is done, attempt to roll it back by doing the above 3 steps. Once you do it a couple times, it will be a piece of cake for you. I've had to do it a few times over the years lol It should only take a few minutes to fully roll back a settled event.