Little would be gained by such tit-for-tat. The behaviour of the Dutch police certainly seems rather over-zealous to me, especially as not all towbars have a dedicated anchorage point for the cable. Sounds to me that some officer is getting extra bonus points (or worse still, a percentage rake-off) on all successful prosecutions.
Like Scotch Lad says, this has nothing to do with safety, it's pure bloody-mindedness.
Going back to the subject of headlamp readjustment, I have been told that Toyota here in Germany actually recommend exchanging the complete headlamp units when coming over to the UK. Bearing in mind the cost of such a conversion, I think that would put most people off coming to the UK on holiday by car. I suspect that the recommendation is just to keep their own backs clean and to avoid potential litigation issues if a foreign registered Toyota was involved in an accident involving dazzle as the proven cause.