You have a situation like this:The label inside the yellow oval is at the end of the curve and even thought you force the labels to show 'INSIDE' of the curve on the label style...
Here is a quick reminder of some cool tools:
1.Select the labels.
2.Hold the Ctrl key and select the label that is pointing to the wrong direction.
3.Right click and select Flip label, this will change the direction of this label only.