You can provide all the assurances in the world that the score is a personal motivator, but we all know that could change at the drop of the hat. I've seen this far too often in the security field. Someone will come up with a great measure, will reassure everyone that all unintended consequences have been considered and then boom. A year down the line an executive, unaware of the ramifications of unintended consequences will want to use the metric for performance evaluations. I think any surgeon who believes the score is only there to help them and that they shouldn't plan for a future where someone pushes to make it more public is being a bit naive in the ways of the world.
This isn't to say I don't think there could be a solution. The scoring system needs to be built from the ground up with an offset risk equation which provides significant incentive to operate on at risk patients. Maybe a surgeon gets three points for operating on the patient and if they die they only loose one. However if they have a healthy patient maybe they start off with one point, with just one to loose. Obviously all the unintended consequences for this model would need to be explored at length.
Well... there appear to be no external controls at this point, either...