Not sure they've said exactly. They do a lot of bonus bets since they updated their platform a year or so back.
Usually they're fairly small so to rack up that amount is surprising but guess they add up. But assuming half those bets were lost anyway not sure it's that big of a deal. Guess a free shot on the horses could be a few scores though.
Racing industry here has been running of fumes for years now so I'd guess much is to do with that.
They've been live betting sports I've never seen and very low league soccer the last week so getting desperate for action.