Not quite. I know the video operator is not a 'referee'. I am talking about the person who operates 'the lines'. And that person(s) is either VAR or works under his instructions. In this case, he/she is either not savvy enough or is deliberately (instructed to) force a favourable result. Bear with me as a bit of 3D imaging, algebra (x-y-z axis) is involved. Some of this may not make sense. Perhaps
@RefJef can explain it better.
The image I posted in post #111 and the image they based the decision on got me thinking. He can't be onside and offside at the same time. One image must have incorrect line drawing. And it comes down to how far the red line (X axis) is continued down from the 'armpit'. In other words where do you draw the horizontal line parallel to sideline (Y axis) to meet the red vertical* line. Once you have that right then you draw the line parallel to goal line (Z axis) to determine offside. The answer is, the horizontal line should be drawn where the locations of the 'armpit' directly projects on the ground, in this case somewhere close to Firmino's right foot. I have added three images here to demonstrate incorrect/misapplication of technology lead to a wrong decision.
* Camera angle means Y axis is not always vertical.
This Looks to be the correct horizontal line on the ground next to Firmino's right foot (shown by broad cast in the first attempt)
Looks to be incorrect horizontal line on the ground about a yard closer to the near side line than it should be (shown by broad cast in the second attempt, I included the horizontal line)
View attachment 3808
Very incorrect horizontal line on the ground about two yards closer to the near side line than it should be. I did this to demonstrate how the operator can manipulate the lines to make an onside look offside. In this case by a foot.
View attachment 3809