[Rich Ives]

The difference with the batter and catcher versus a runner and fielder is that the batter is concentrating on the pitch and cannot even see the catcher. No awareness is required or desirable.

There is also NO obligation on the part of the batter to avoid the catcher prior to the pitch passing, but there is an obligation on the part of the catcher to not interfere/obstruct the batter's ability to hit the ball if he chooses to attempt to do so.

The catcher lucked out - he didn't take a swing on his hand/arm. The positioning I learned at coaching clinics was to be able to touch the batter while upright on the knees, then rock back into the crouch. A touch from the crouch gets you too close.