The other anchors were bowlines, he had the rope but didn't know how to tie the knot with a bight. Two problems with using carabiners, a single carabiner is a point of failure and, yes, people steal carabiners from anchors. It is more common at Great Falls but not unheard of at Carderock.
The nice fat rope is a good anchor, the tiny cord with single wire gate carabiners, not so much. He's using a cam and a nut, prone to ripping right out in the rock. Somebody asked if that was a myth. We live in a city of stone buildings, not one made from this rock, it is never used where it would be weight bearing.