Actually, the dolphin kick used by the Japanese swimmer was not alleged, it happened. The showed it on replay. Underwater cameras, you know.
He evidently was just told, "that's a no-no, don't do it again" because he didn't do it at all in the next race.
There was discussion by the commentators about all of this the other night.
My daughter is a swimmer. No dolphin kicking on breast stroke is allowed, period. OK on the other three strokes.
My analogy appears apt after all.
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.