I had a similar thought with regards to high stakes gambling (pool, poker, golf, backgammon and prop trading). When you learn to do any of these one has to learn how to deal with making decisions under time and money pressure. Everybody that has ever played a sport competitively has made mistakes under duress that are difficult to explain later because your mind shuts off during that period. This is probably a limbic response to stress - your first instinct under danger is to switch to flight/fight and may not be using the framework that 10k hours (or however much time spent) built. Everyone can get better at moderating their response to this but I suspect that some people are naturally better suited at shrugging off the blaze of autonomic responses and still be able to focus on the task at hand properly. The people who attempt to put in 10k and fail because they can't handle pressure aren't accounted for. It makes for a nice book but saying 10k hours is all it took Michael Jordan or Gretzky or Mozart to hit their "master level" ignores this survivorship bias.

I think Jason has a good point that hitting a golf ball and being able to function under pressure are two very very different abilities and professional golf is most likely selecting for both abilities.