You might have misunderstood the part about the kick, that was more Sigurd mentally preparing himself to react to a certain move as opposed to any physical action, as all of his actual actions were simply him fleeing as quickly as possible (including dragging his legs away).

Also not quite sure what you mean about it being hard to see coming, the knife is in Gigue's right hand in my understanding, he would have to reach over and turn his entire upper-body leftward to strike at Sigurd as he escaped, seems pretty telegraphed to me.