Game Mechanics: Get skill up message but don't skill up

[BarackObooma]

I have a level one mule in EC that I use to corpse no rent items so he dies a lot usually by a one shot from a merchant.

I've gotten the message "You have gotten better at defense (5)" dozens of times but if you look at his skills, his defense is still 4.

I'm assuming it has to do with him dying at the same time (or possibly before) and therefore negating it but would think it's a bug either way since it gives the skillup message when it isn't or that it isn't giving the skillup.