Still don't know how it would ever work, given that the player would basically need TAS-like reflexes to hit the button at the exact frame every single time without fail, not to mention the machine lags when taking a win (e.g. playing on while it's still counting up) or when there are many animations and/or flashing symbols happening at the same time (and/or any music that was still playing). Miss the timing by even a millisecond and it's going to be a completely different outcome. Even on a 1980s machine it would be next to impossible to cheat like that. Never mind the amount of time it would take for the human brain to acknowledge the guy on the phone saying "now" or whatever and then performing the action.
If anything, it was genuinely advantage playing - finding a slot which wasn't set to a crappy amount like 87% (otherwise known as variation 99) by checking the reels. Of course you'll win more frequently if it's set to 95% or even 97%. Set all of your home machines to variations 3 or 4 and you'll notice they become a lot looser than the casinos too.