But if the tube the water comes out of is pitched, the weight will be heavier on one side and influence the direction of flow.
Being in construction, if the water went clockwise I would want to know if the toilet was out of level with the right side lower than the left.. and vice versa.

As Pat mentioned, I also think brand (and model) would be a factor. American Standard here (2) both clockwise when viewed from above. I'll have to get out the level later.

I do not work here, but the benefits are still awesome
Make your sound your own!