It's a three, unless he marked it and replaced it and then it blew in (which didn't happen in the scenario I gave).
Did you look up some definitions in the Rules of Golf?
I'd look up "outside influence" and "natural forces" (those are just the same link FWIW).
I'd recommend you look up the definitions.
Then look at Rule 9 - Ball at Rest Moved.
I remember using "Easy Liquid Sander" (available in the paint section at Home Depot) to re-vitalize some grips years ago. Haven't used it recently on any of the newer compounds, but you may want to experiment with it. Made those old smooth rubber grips nice and tacky. Jet wet a rag with this stuff, rub the grips and let dry.