That's the only thing you saw because those are his only knocks right now, and those are still negatives.
I would take him in the second but no way in hell with our top 15 pick.
If you're drafting an offensive linemen, you draft a guy who is proven and has played the position a while. You don't draft based on potential.
I am not sure id call them knocks when they dont affect his play or show up on tape.
In Johnson's case it is a plus / positive that he is raw and new to the LT position as he did very well there and held his own against some of the top pas rushers in the NCAA last season.
Obviously you would want I guy that has produced at said position for awhile but you cant always get that. He produced when given the chance and that is all you can ask for.