Mine have mostly been misclicks/nudges when theres a max bet button next to the spin button.
It’s such a bummer when this kind of thing happens 🙁 make sure you check the spin cost before pressing it. I know 6 acrobats used to automatically load at £22.50, book of dead was £2. They all vary. Not sure why you wouldn’t have checked before pressing spin though? I don’t think anyone would just load a game and press spin? I don’t know maybe I’m being daft, but I wouldn’t.