Some federations strictly prohibit the use of film (ie replays) to detect such violations. One example is the Federation Internationale de Basketball (FIBA), which has long prohibited television replays from determining the outcome of events. That resulted in a Serbian protest of Argentina's Emmanuel Ginobili's off-balance jumper at the horn which gave the World runner-up the win over the World champions earlier in the week being denied, since FIBA prohibits replay from settling disputes. Ginobili, a member of the NBA's San Antonio Spurs, would have probably seen NBA officials watch the replay on a monitor to determine the validity of the shot.
I don't know FINA (swimming) and its replay policy, but if replay cannot be used to call fouls, then they can only warn, not disqualify.
I don't know about the use of cameras for swim, either. I just meant that we were able to see what happened because of them.
According to another thread I took part in someone said the Japanese swimmer was seen doing the dolphin kick on the Jumbotron and everyone started booing...most likely swim parents, he said, LOL!