There is a known bug/feature since the initial release, where if you have one level in Sword Expertise and Augment damage, after saving the game and reloading you will have 2 levels (this works for other characters than the male warrior, but they have to put the first skill points in themselves).

If that happened more than once, then it sounds like a bug. No one else has reported this AFAIK, so it may be a rare glitch, or possibly something specific to your install/system.