The ball is on the 14 yard line. #83's front foot is on the 12. The slot appears to be on the 11. The OLine are all across the 13. It's a ticky tack call. #83 is lined up behind the line of scrimmage, technically. But still, it had no impact on the actual play. I am sure this happens quite a bit and isn't called. It's not as though he was trying to fool anyone.
I do agree that the way the receivers are lined up in relation to each other shows no deception to the defense. So in that sense you can maybe let it go (as the rule was put in place to prevent deception). I think had Duval been only about a half yard or maybe even a yard behind the LOS with Dupree being a yard behind him, maybe it isn't called. But he was, as you said, almost 2 yards behind the LOS. At that point to the ref, it makes it almost impossible not to call.
If both were behind the line of scrimmage it made Alexander an eligible 7th receiver at tackle. That is a deception to the defense, intended or not. They had to call it.
I don't know about the college rule but in the NFL the team that wants to run a tackle eligible play must inform the officials.
It doesn't matter. If they still line up 5 men in the backfield, it is an illegal play. To make a tackle eligible, you have to put somebody else on the line on the other side of the field.
from kleinpeter "Referees don't tell you if you aren't on the line, like coach Les Miles suggested. They will tell you if you are offside or not and he wasn't." http://www.nola.com/lsu/index.ssf/2015/09/grading_lsus_34-24_victory_aga.html#incart_river
Ritter did not throw that flag. The side judge threw it. Also, this was not a SEC crew. The crew was a mixed crew from the SEC and ACC.
Yeah, I wasn't quite getting the referee giving the receiver the nod as to whether he's lined up correctly.