These days the software can be rigged from an insider. It can be programed to produce a win after a certain sequence of events that the player is privy to.
Very unlikely that things were not rigged.
I wrote slot machine software for a couple of years. You COULD put a cheat like that into the code, but you’d have to get the 2 other employees that check you code, and approve it to go along with it. Which could happen, but then you’d ALSO have to pass the gaming control board’s investigations of the code, and maybe GLI (Gaming Labs International).
All of which have seen this type of thing before, and they’d be able to trace it RIGHT back to the author.