A lot of people have cheated with the whole world watching, it isn't really that hard. Main thing is to act nacherally! I watched a player slug rack himself for the entire one pocket event at DCC one year. A well known player so countless people saw it, I never heard it mentioned. Rack the balls normally then pull everything behind the front two rows back. Those racks looked like they were superglued!
Major league baseball, football, many olympic events, bicycle racing, many things with far more officials and spectators than pool, cheating often goes on long term. When I caught my opponent cheating on a pool table gambling I sometimes blatantly cheated in return. Sometimes I made more balls with my left hand than my right, and I was shooting right handed. A little misdirection, a flick, it has been working for stage magicians for centuries. My usual move was just head games. Nothing harder to catch than someone pretending to cheat! Makes the opponent crazy.
Cheating may be happening in plain sight, it wouldn't be hard to do Opponents getting the gooey end of the stick are going to have to protest while the cue ball can be checked, not just bellyache later. I think the catch is they think they are being cheated without being 100% positive. If you scream and no cheat is found then you look like an idiot or cry baby.
Hu