Golf - the "Gimmee"

[mick]

Today, in a final playoff hole, J B Holmes was laying 5, and Paul Casey putted just inside Holmes and was laying 4.
Casey putted in for the win (I assume he asked permission), and then picked up J B Holmes' ball marker and handed the marker to Holmes.
Seemed like a polite, golf-like gesture.
Of course, Holmes putt would have been moot, but I wonder if anyone here can give a rule for tournament play in the PGA, with respect to a "Gimmee", or is there no such rule, aside from that Match Play stuff.
Thanks.