I'd suggest you go back and re-watch the play.
A) Labhart was "camping" at the 19-20-yd line (19 is LoS), wide-open for approx 3 seconds while Johnny progressed from his right to left. Labhart is the only receiver to JM's left.
B) If JM throws to Labhart initially, you might get a 5-yd gain, not a TD. The DB is playing off, but not unaware.
C) #82 was creating pressure from the back on JM's right side, collapsing the pocket forward.
D) JM jumped over #52 trying to make a run up the middle, instead the guy catches his ankle and slows him down. As additional pursuit closes in the middle / left, JM breaks back and left.
E) The CB covering Labhart releases only AFTER Johnny gets his release to the left post-jumping #52.
So, this isn't a "clean pocket", jump a guy for no reason scenario.
Oh lordy, gonna make be bust out the screenshots are ya?
A. First off the called play was a fake screen to Labhart in order to get Derel Walker open deep down the sideline. The fake worked, Manziel looked over to Labhart right after the snap, causing the safety to hesitate and let Walker get behind him, Walker also beat his DB off the line and had ample separation heading into the end zone.
[IMGwidthsize=800]http://i42.tinypic.com/160edcx.png[/IMG]
I used yellow lines to demonstrate the amount of separation Walker had on both Safeties as well as the CB covering him. The safety on the top left has his hips facing way from Walker and is in no position to make a play, the second safety is 20+ yards away from Walker and the man covering him is 2 steps behind. Meanwhile Johnny is standing in a clean pocket with plenty of time to throw, instead he doesn't recognize the open Walker and took off up the middle. Side note; he has Labart wide open for a safety valve and a possible first down, and even has Evans coming across the middle with a step on his defender.
B) You are mostly correct, the Safety had his eyes towards Labhart because of the initial fake screen, but he was still very far off and a first down completion could have been made. Again notice in the next pic Manziel sees Evans coming open, but doesn't stick with him and takes off instead. Also notice in the below pic the aforementioned Derel Walker beating his guy off the LOS, #14 the CB has his hips towards the sideline while Walker has already began to streak towards the end zone
[IMGwidthsize=800]http://i42.tinypic.com/2enuhy8.jpg[/IMG]
C) Not really.
#92 was being blocked by potential first rounder Cedric Ogbuehi (who just announced he is staying for Sr season Whoop!) #92 starts flying towards the back to try outflank Cedric, but big Ogbuehi wasn't having none of that and just rotated with him and never lost contain. Take a look at the following picture. This shows the exact moment Johhny decided to take off...this pocket is the definition of clean, not a single defender within 5 feet of him. A pocket this clean will rarely be seen in the NFL, and Johnny regularly sees a pocket like this due to playing behind the best line in CFB the last 2 years.
[IMGwidthsize=800]http://i41.tinypic.com/2ikp8q0.png[/IMG]
D) I say he jumped a guy for no reason because he should have never taken off in the first place. Obvisouly the jump was a nifty move, but like you said the defender grabbed his ankle and the play would have been over with Johnny falling to the ground if he hadn't bounced off the back of big boy Jarvis Harrison.
E)There was never a DB covering Labhart, he was open in the flat from the get go and the safety didn't come down to pick him up, he came down because Johnny started to run and he was coming down to make a potential tackle like a safety is taught to do.
First picture below shows Labhart just sitting out in the flat with out a any DB covering him, the DB in the top right corner is turned around and chasing after Walker. In the second picture you can again see how wide open Labhart is, I circled him with a yellow circle because I feel like John Madden. The safety is has is eyes on Johnny and has broke coverage of Walker in the endzone because Johnny had just began to take off.
[IMGwidthsize=800]http://i40.tinypic.com/rw13tf.png[/IMG]
[IMGwidthsize=800]http://i41.tinypic.com/30svtle.png[/IMG]
My whole point in rambling on about this one single play, is because it is something that I have seen happen pretty often the last two years. Johnny ends up making a play, but it isn't always the best play from the get go. Do you really think something like this would have happened in the NFL where he bounces off his own lineman and then runs all the way out of the mess? Not me, in the NFL this would have been a QB run for little gain and O'Brien would have been screaming at him because he had multiple guys open for positive gains.
Again, I love Johnny, and I think he has the potential to improve his bad habits at the next level, but we have to deal in the facts, not the hypothetical.