Courtney, it's actually 50 ft threshold crossing height, which would mean a touchdown point roughly 1000 ft into the RW. Whereas crossing the threshold at 50 m on a 3° approach would mean a touchdown some 3130 ft down the RW....
If the requirement really is to have a clear area to account for an aim point 60m short of the RW threshold, then that would imply a minimum height of only 14.8 ft over the near side of the A15 on a 3° approach....which equals 4.52m.
Anyway, enough of the trigonometry. Because however you look at it, standing underneath the RW approach that close to the A15 is utterly stupid - and most certainly 'Darwinian'!