A friend of mine was remarking how linesmen are now completely redundant. I mentioned to him that they still have the job of judging conversions/penalty goals. It seems as though they are pretty useless at that as well...
Part of the problem is the colour of the ball is the same as the goalpost.
When they were using leather balls, it wasn't a problem in making a decision in regards to the ball passing the post.
Maybe if they painted the rear half of the posts with a thin black vertical stripe so the ball would easily stand out.
Players converting wide out wont be affected being the angle wouldn't be so acute.
Or save time and money have the bunker judge whether it was a goal or not.
(That last sentence took me 5 minutes to type because of the tears of laughter)