Nice reply - cheers.
The engine sounded normal and everything felt normal which is why I didn't instinctively chop the throttle immediately as a reflex reaction. I just didnt see what I expected to see so consciously and deliberately scrubbed it purely based on the numbers not looking good and completely ignored the physical indications (sound, speed etc) which were normal.
I wonder if my decision would have been different if I flew the a/c day in day out and knew it intimately as you describe with your Pitts. Interesting point....!