Champion's Stand vs Orc Rush

So I have not had the skill before and only used it successfully once so far. Unfortunately, it did not do what the helpfile says. I do not have a log and have no tried to repro it yet, because it is so obscure. Plus, I don't know how the orc skill works. Basically, communed champion's stand, orc rushes in and bowls me into next room. Does champion's stand have a chance not to work, or was it never programmed specifically to the orc skil? I figure this might be the case considering the constant revamp of orcs.