Now that I look at it I kinda agree with JC. Maximum of 30 seconds. If at 20 seconds in the kids run in the middle of the fairway or a park walker shows up right in the area you're about to throw to, then I give you that you shouldn't throw right then. But when those two distractions are gone, you now have 10 more seconds until your maximum of 30. I think if they had meant an "uninterrupted" 30-second window then the word "maximum" wouldn't be neccessary.
You get 30 seconds after those 3 criteria are met. Not 30 seconds of those criteria being met.