One of my biggest ever wins came from a "mistake" actually.
Was playing gonzos quest on my normal 20p highroller stakes.
Game crashed so i reload and start up autoplay again, without noticing the bet has been reset to €2 instead of the 20p i was playing.
Bonus after 2 spins and a 350x win.
Took me like 3 spins into the bonus to understand wtf was going on.
Gave me a decent hit that i figured would be around 80x, but for some reason it paid 800x.
Then i noticed the stake and the bonus got very exciting all of a sudden.
Won just over €700, and i think thats what they call a happy accident.
Still dont come close to the €2300 i won on Doa2 while betting 9p.
So moral of the story is, never bet above 9p.