All you need to feint toward third is to step toward third (and not make any motion associated with your pitch). When throwing to second, you can rotate either way.
what he tried to do: 1) feint toward third by stepping there, 2) break contact with the rubber (although that's not really needed in FED) and become an infielder, 3) throw to second.
It's just a variation on the 3-1 play.
he just made it "too tricky"
So in a sense - aside from where he stepped - in FED it would be a legal move, but not where OBR is used?
As of last year, this would not be allowed in OBR because it's now illegal to feint to third. Some youth leagues have NOT adopted that rule change. In those leagues, and in NCAA, it would be legal (in a general sense) to feint to third, break contact, then throw to second.