[RKBUmp]

It has absolutely nothing to do with when the pitch starts. The pitcher can commit an illegal act before the pitch ever starts, such as stepping on with hands together, immediately bringing hands together after stepping on, licking fingers and going straight to ball, rubbing dirt on the ball, grinding ball in dirt etc. All illegal acts immediately when they happen. There is no recourse to correct an illegal act once it has been committed. Your UIC is incorrect and he will not be able to show you any case play, clarification or rule support to back his position. Nothing in any rule set give the pitcher the ability to correct an illegal pitch.