MainzMan: If you take a putt and get the new ball brought into play then I'd submit a report to WGT as this is very much wrong.
Unless the putt is from the fringe...these count as hits to my knowledge,
Edit
MainzMan: I've had balls replaced when on the green but that was always after my approach shot, never after a putt.
Not so sure on that and have never taken too much notice, but it would make sense that the ball is replaced after the putt - so the approach would be the last recorded hit on the ball as putts do not count, and the ball is then replaced on the tee as you can do in real golf.