IlDuce: Developments since last post, the garage refused to believe any paperwork I presented to them, I then investigated official complaint procedure, but was put off when I was told something to the effect of garages can use whatever test they like, and we won't say thats right or wrong way to do it.
VINZ, VTNZ, Honda and 3 small garages all said the test method used on my car was wrong.
However in the end I needed the car for work so couldn't play around any longer, so I booked the car in for replacement of the (most likely) perfectly good ball joints at another garage - and when they went to change them, they rung me up and said there was nothing wrong with them at all, and so issued a new WOF instead.
oh dear ... i got done by ball joints too! on my mitsi diamante when it had done about just under 100,000ks ... it was tested at VTNZ ... that was years ago though ... who knows whether they actually needed replacing or not!