Never owned a dog with a even score they are often a couple of points apart, is this down to early damage or is some difference between the sides normal.

I would have thought that was normal bodies are rarely equal on both sides I am thinking human here. Interesting to hear what the people who know say

It's very rare for a living thing to be completely symmetrical, so a point or two's difference in sides is normal.

One or two points is normal.  I've only had one that has had the exact score on both sides.

I would say a couple points difference is pretty normal.  The last 2 dogs of mine that have been hipscored were 3:3 and 4:4 though.

According to reports I have read by Malcolm Willis a couple of points difference is the normal differences in symmetry and/or a slight positional difference when taking the plates.

Looking at my own pedigrees the difference between hips is usually less than 3 points.