So i just tested this in SV and apparently showdown had it all wrong, what happened on stream is in fact the correct behaviour of sucker punch.
Since i am a man of my word, i will post this picture as i agreed i would i was wrong with @peppemusicco
@Queueueue_@playpokemon I don't think it has ever come up in SV for me, so i might very well be wrong here, but on showdown sucker punch doesn't fail
https://t.co/gJRlbi3uwU
@gen_shun Thank you! it would be very cool if you added the option of selecting RNG events (like always crit a certain move or select a specific roll for an attack)