Yea, that game (HERE) is a perfect example of things that have be talked about over and over here on some of the backgammon boards.
The "real" backgammon rules state that a player must use both dice if possible. Here at BrainKing, it does not enforce that rule. (So some players call it cheating, yet others call it OK since it is allowed).
I'm not sure what Fencers feelings are on the subject - since he is the "main" person, he would be the one to decide if the move should be allowed or not. (I'll send him a message and ask) - I'll post a reply or ask him to! :-)