Because Gelnn Dorsey said so! The way the rule is written, covers the number of men on the line of scrimmage (not their location on the line). You can line your left tackle out wide to the right (like Ciron Black did on that play) on the line, but he cannot go out for a pass. Dickson was actually behind the line of scrimmage, making him elligible. Remember that ignorant formation Florida tried, where the whole team except the center and Tebow where split way out to the right? Same principle as that play, except the formation is designed to look more like a normal formation.
Nutria, Dickson was lined up on the line scrimmage, that gave us 5 lined up on the line as "linemen" and then Ciron Black and whoever the receiver was that he was covering. When I watched the replay, I said to myself, what LSU receiver gained that much weight? I figured maybe there was something to Fisher's blogs...lol That's when I noticed Dickson was lined up as our left tackle.