Any class is at a disadvantage if the opposing lock is a good player.  Any lock is at a disadvantage if the opposing class is good.

I've wiped the floor with warriors before because they werent sporting the right gear (usually pve geared so fear breaker trinkets) or they didnt know what to do at the right time.

I've also beaten and been beaten by feral druids because we both knew how to read the other.  The outcome of a 1 on 1 duel has little to do with the class and most to do with the player.