To those who are bored with Brough's DG attempt, or those who are irritated by analysis and discussion, I suggest you look away now, or go do something else. If you choose to stay then don't blame me for your own stupidity.
First of all many thanks to those who have entered into the spirit of the investigation, and made numerous theories, arguments and provided images which have shed a lot of light, from many angles on the question, and raised a number of good (and bad!) points.
This will be my final post on the thread as I've reached my own conclusion, taking into account all serious posts, and leave you all to analyse it, critique it, agree, disagree, lock it, debate, wind-up or whatever floats your respective boats.
My final Paint and crayons effort is below. Thanks in particular to the poster who reminded me that we have a third, side on, video to add to the front and rear, which can actually be used in conjunction with what we can learn from those others.
Notes:
We need to know the approx distance from ball to posts, and posts to known point of impact with back wall. The first is known, how to work out the second?
Line A on the far touchline follows the touchline. That is the horizontal.
Line B descends from the plane of the glass in the hospitality boxes, which the ball hit. It is very slightly 'out of true' due to correction of parallax in the TV grab, but is such a short line it makes no difference, and is at that angle because it follows the vertical of the corner of the stand.
Where A and B intersect is where ground level would be, if the stand did not exist.
I've then shaded in a section which is a virtual 'black glass wall" extending the glass in the hospitality boxes. Conceptually, think of this wall as "behind" all the seats. You can ignore the seats and it is best if you do. If you cannot remove the image of the seats in your mind, then at least bear in mind that they are IN FRONT of the glass wall. Not behind it.
Line C is of course the base of the virtual glass wall, level with and parallel to the pitch. If the stand had not been built, imagine the grass extending all the way to Line C.
Next we need to know where the centre of the glass wall is, in terms of the centre line of the pitch.
Line D is the centre line. This is checkable from 3 points of reference through which it therefore must pass:
i) the centre notch in the 20 metre line
ii) the centre of between the posts
iii) the middle seat of the bottom row.
At the right edge there is one yellow vertical and one red. I have corrected the parallax as far as I can to get all lines and the posts to appear about vertical on a flat image but there is still a slight "lean" to the right", please note this doesn't make any difference as whether the line appears vertical or not, parallax correction equally stretches the whole image. (But it's actually a composite of 2 different screen grabs anyway).
The yellow line is thus the vertical relative to the centre of the pitch.
The red line descends from the point we know the ball hit the glass. there are two points of reference fro that, one is the image of the ball actually hitting the glass, another cross-reference is the number of ball-widths the ball was off centre line immediately before it hit the glass. All are consistent
It intersects Line C at ground level.
Finally a red line connects the approximate point of the kick to the red vertical.
As we now have a means of knowing that the red line is level with the ground, we can work out where it intersects the try line.
Unfortunately, this does not provide conclusive proof. It indicates that the ball or a part of it would probably pass "through" part of the post. It would not be wide to the left of the post, but there is a margin for error and the ball could hit the post, or could just scrape by the post, or go in off the post.
My opinion now, based on all the evidence, is it probably was a DG but I do not now believe - as I did - that there is conclusive evidence. I also know that the posts according to the rules extend indefinitely upwards - but how wide is the virtual inifinite post?
My conclusion is that Bentham probably should have let the VR at least take a look, but in the evnt this would have made no difference in that it would have been unfair for the VR to make a call unless there was by fluke an actual directly in-line angle, which there would rarely be. I still think that it probably was a drop goal, but I have reduced the probability to "slightly more likely than not" which is not enough to say Bentham made the wrong call.
I am certain that if anyone could be bothered and if they had access to the ground, a plan, and the relevant equipment, the red lines could be refined and drawn with considerable precision but whilst you could show the track of a ball along the ground, because it would on any calculations still turn out to be such a close call, you could not, I believe, ever prove that as it passed the plane of the posts, especially given the height it reached, it was precisely on that exact line.
And on that note, my work here is done. Phew.