This is an overview of other oddities that i've found so far.

1. Model 889

Later version came with additional inlay.
2. Model 6781

Two different versions of backside picture.
3. Model 6841

Only on the backside of the box you can see that the 2x2 sloped brick in front of the driver actually has a printing on it.
4. Model 6842

Some but not all directions do display a yellow helmet on the red astronaut.
5. Model 6844

Both directions and photo on the box do show a 2/1 finger hinge in blue. In fact this piece has never been in existance in blue. There is actually one in yellow in set 6950 (and a red one in technic set 8859).
6. Model 6894

The backside of the european version of the directions is different. That's because the 6954 renegade has not been available in europe.

7. Model 6921 (no picture)

This building instruction exists in black/white and colored.
8. Model 6927

Simply see the picture. Grey on yellow is correct.
9. Model 6929

Only if you are the proud owner of the box of this set you will be able to complete it. The contents of the container aren't in the building instructions but on a small picture on the long side of the box.
10. Model 6938/1737

Pictures on the frontside of the us-box do show a different configuration of the two loading arms. The eu-box shows the actual set version only on the frontside.

Another oddity: us-box 6936 says "cont.197 pcs" while box 1737 says "cont.196 pcs". I still do have to investigate what the missing piece in 1737 is.

11. Model 6970

The backside of the european version of this direction is different due to the fact that 6901 and 6861 have never been available there.