[quote=@Vordak]
<Snipped quote by MelonHead>

My impression was that the step back was initiated as a reaction to the strike, not prior to it. Guess that's why the chronology is off.
[/quote]

The step back is in response to your character stepping forward and winding up his arm, but it's the pull back of the shield that saw the attack hit thin air. It's very possible for Sigurd to step back, pull his shield back, and feint an axe throw in one movement, in fact, the act of pulling back the shield would make it easier. Give it a try. 

Therefore I'd expect your character to be pretty much in front of Sigurd and nearly wide open as he feinted with the axe, if he had loosed the weapon and your character relied simply upon speed to move out the way it likely would have hit him.