After the India stage (I think) I popped open the Switch "Emulator" menu (the thingy with the reset/save state options). This may invalidate the run; no states get loaded but I know that for emulator runs, using emulator features can invalidate the run, and I guess technically you could pause buffer with that (though, wow, that's desperation).

[Mod edit: It was an accidental press, no biggie :) ]