Lies on a slow news day...

Illegal?  I say bollocks to that!  MSM with nothing better to do on a slow news day, whilst teachers are still enjoying their 13 weeks of holidays, but that's another story.

The law is quite clear:

2.9 Passing where roadway marked with no-passing line

(1) This clause applies if a driver is at or approaching a portion of a roadway where the road controlling authority has, in accordance with any enactment, marked a no-passing line applying to traffic moving in the direction in which the driver is moving.

(2) The driver must not pass or attempt to pass a motor vehicle or an animal-drawn vehicle moving in the same direction within the length of roadway on which the no-passing line is marked until the driver reaches the further end of the no-passing line, unless throughout the passing movement the driver keeps the vehicle wholly to the left of the no-passing line.

Nothing about crossing or being on the wrong side of double yellows, just as long as you are not executing a passing manoeuvre.

Unfortunately the revenue gathering bastards would likely get you on a 'driving carelessly' fish and chip type catch-all.  The Manawatu Gorge with plenty of opportunities for 'straightening your drive on s-bends' is another favourite venue for revenue gathers to take your photo.