Maybe he'd been following him all 4 days of a tournament and got tired of watching Phil miss fairways and chunk it back on.
Maybe his PGA Tour groupie Dad drags him all over the place to follow Phil and he's seen thousands of Phil flop shots.
At what point does it stop being a sacred experience?
I used to play with a guy who would have a muscle spasm on occasion and let the club fly behind him on his follow through. Once, when his 6 iron whizzed within millimeters of my head, I learned never to stand behind him.