You CANNOT remove umpires call.. that is the tolerance in the tracking software... It's obvious that this key point is being missed and it's actually quite alarming how many on the game don't get this
I have heard that before, but have never seen any published info on how far out the tracking can be. If it's exactly half a ball width, that sounds like a strange co-incidence!
Interesting that in tennis they use what I would guess to be a very similar system, but have no trouble over-ruling an umpires call even if tracking shows the ball missing the line by a millimetre.
Tennis players and fans accept the system as being 100% accurate, while cricketers assume it's not accurate by half a ball width.