Seems their protocols worked. Several people tested positive and dropped out, some due to positive tests some due to contact. I guess we'll see in the next week or two whether those few positive tests turn into a lot.
You're not going to prevent all positive tests, the goal is to avoid having the virus spread rampant throughout your competitors.
They're updating the protocols which is a good sign.
https://www.golfdigest.com/story/pga-tour-announces-adjustments-to-protocols-following-second-pos