Some time ago a saw BA767 cross a lit red line-up bar at LHR 27R after receiving instruction to Line-up 27R, cross the stop bar. We went behind to holding point and later received instruction to line-up with the bar still lit (not going off soon after the instruction, respectively). Both crewmen agreed that it was the same case as previous and we proceeded to cross it at which point I included the information in my readback. Line up 27R and wait and, eeh' we're crossing the stop bar? ...
The answer was a simple NO.
FD.
PS: at LHR exit from Q to B the stop bar is malfunctioning, i.e. the two right most lights (three on each side of the centerline) are lit permanenetly. I advised the polite gentleman on ground freq. about two weeks ago but this week the problem was still evident. Perhaps some of loyal readers have more leverage over this than the ATCO?