Whoah! Its geting hot in here! I almost tripped on the tension. It doesn't matter man, people are going to have differing opinions, some people believe that you should stick to perfect form no matter what, and others think, as long as it gets the job done, whats wrong with it (especially for complete beasts like that). The dude could prob lockout if he so wished, that kinda weight could prob crush your elbows, as in jam them, if he locked out completely, whereas keeping his elbows bent the weight is evenly distributed throughout the mechansim (his arm). In my physics class we had a experiment fairly similar where we took a bar with tension cables running all around and had a joint set between it and anoher bar, weight was placed on top. When the bar was straight the tension on the joint was at its highest, whereas when it was bent it was distributed better meaning less newtons per cm. The arm will work much in the same manner. This worked the same when the weight was hung from the bars as well, but this can't be applied to a deadlift because the give will not be in the arms but in the back. In that lift the arms merely act as cables in which the tension increases but the pulley itself is the lower back and inevitably the upper back as well.