coppers are w*****s wiv that sort of thing. i had 1 few years back where the overhang behind rear wheels on my escort van,and only the overhang!, was above the zig zags (i.e if touching floor woulda been touching the zig zags) and i was there only a sec and didn't realise. i also got 3 points and a fine
this was 4 days b4 xmas too, what an a******e. what i later found out was that i coulda gotten away wiv it cos he didn't move me off of them to nick me either!
from the quotes others have put from highway code looks like u wont get away wiv it, however u might possibly get the points dropped and just have an increased fine, due to the circumstances in ur case. at least thats what a friend of mine thinks but he's not qualified to say so, just knew of a similar thing (tho not zig zags) happenned to someone else.
GOOD LUCK