Rule 6.06(c) and 6.06(d) Comment: If the batter interferes with the catcher, the plate umpire shall call “interference.” The batter is out and the ball dead. No player may advance on such interference (offensive interference) and all runners must return to the last base that was, in the judgment of the umpire, legally touched at the time of the interference.
If, however, the catcher makes a play and the runner attempting to advance is put out, it is to be assumed there was no actual interference and that runner is out—not the batter. Any other runners on the base at the time may advance as the ruling is that there is no actual interference if a runner is retired. In that case play proceeds just as if no violation had been called.
If a batter strikes at a ball and misses and swings so hard he carries the bat all the way around and, in the umpire’s judgment, unintentionally hits the catcher or the ball in back of him on the backswing, it shall be called a strike only (not interference). The ball will be dead, however, and no runner shall advance on the play