Thats because the player had a 1h equipped when he transformed. If he had been a 2h user, it would have raised 2h.
Is this confirmed by someone who transformed with a 2h equipped? Also, what if I have no weapon equipped, like if i'm a mage... does my magic increase?
If it's based off of equipped weapon this will be a neat way to level melee skills i wouldnt want to normally level.