Nah, that's not a defensive stance. It's an offensive stance. It feels logical to me that someone who wanted to punch hard and fast would keep one hand at jabbing distance, and the other drawn back to dish out heavier strikes quicker. With both hands in front of you, it's easier to parry an attack and do swift jabs, but you have to retract one hand in advance if you want to perform a more powerful punch. In a stance like this, half the work is already done. Helm's resketch looks a little better than the original, though, pose-wise. That elbow needs to jut out a little, be a little aggressive. Elbows never really stay close to the body unless you're simply letting your arms hang down.
Other than that, I'd have to say I love it though. It's a very nice and clean sketch, and it's generally a successful pose.