To be fair, this is a load of nonsense and I can't believe I'm about to bite.
It doesn't matter whether Dawson had x-ray vision or not, nor whether Flint is stood up, crouched or being fellated by the referee when the ball is kicked. He's stood in an "offside position", that's not up for debate.
What is up for debate is whether he is "interfering with play", which is course he is; it was obvious at the time and it was admitted after the event - he was there to make a nuisance of himself.
In what way is he, in his own words, making a nuisance of himself? There were 11 Sheffield Wednesday players on the pitch, ten of whom were further advanced up the pitch than Flint and looking away from him. There was one Sheffield Wednesday player who he was directly in the eyeline of, doing star jumps.
The player Flint was distracting and getting in the eyeline of is the player in the position which most relies on reflexes and reaction time, slowing that reaction time down by even a single tenth of a second is the difference between a goal and a save.
Whether the ball ultimately follows Dawson's line of vision or not is not totally irrelevant, so you do kind of have a point, however it's the opposite point to the one you are trying to make. If the ball follows Dawson's line of vision (as interfered with by Flint) then he makes a comfortable save whether or not Flint is there, but it doesn't, the angle of the ball means that Dawson needs to make quick lateral movements to get across his goal and make the save. His movements are slowed down, his reaction time is shortened by virtue of Flint blocking his view.
Saying Flint isn't interfering because the ball doesn't follow Dawson's line of sight is like saying the pillars on the Kop don't obstruct your view unless the ball lands at your seat.
Going back to your snarky content about x-ray vision allowing him to see through the wall, again you counter your own point. The wall massively blocks the goalkeepers view, but it's placed there to reduce the opportunity for the free kick taker to score - he can no longer drill the ball into the corner, he'll have to float it around or over the wall. Hopefully the keeper will react to the 'softer' shot and be able to save it. Once built the wall doesn't move, it doesn't do star jumps or duck. If it was a wall of Cardiff players (and it had no defensive player between it and the goalkeeper / last line of defence) it'd be 1000% offside as a result of blocking the goalkeepers view, but it's not, it's a defensive wall built by Wednesday. What isn't a defensive wall built by Wednesday is Flint, stood in an offside position and interfering with play.
He's offside, plain and simple.