Remember the Pinehurst easter eggs? All those pictures that have no flash overlays were obtained the same way.
And also the way the Easter eggs, and bigfoot, got there in the first place (I presume).
Last I checked, the eggs as well as the squatch are still there.
I would think the helicopter, then, was during the mapping process. I found this pic, a while back, taken by Stonecoldkiller. It shows all the stuff used by WGT during mapping which are later taken out by the programmers.
My understanding is that when Nico and others were first trying out PGA National, there were things all over the place.