Seems to be doing the opposite effect.
It's not really but the end result is it kind of is. Oddly it only happens to one object in this file. This is customer supplied so I'm not sure what might be different about this particular object but when I do a negative .25 pts on the offset path everything acts normal except for the little leaf, it actually grows!
If someone could take a look and see if they understand the issue better than myself. I am VERY limited on my illustrator knowledge and the wife is out of state.