WoWInterface - GetItemStats not returning all stats

Hi all,
I'm trying to get stats from items with this method, but it seems to behave differently based on how the item appears to the player (i.e. Dribbling Inkpod - 169319 for a warlock returns agility, for items with int/str it return intellect). Is there any way to get all stats (not just the valid-ish ones)?
I see it has to do with the item link (check the :::120:...):

Lua Code:

-- 266 - demo warlock
"|cffa335ee|Hitem:169319::::::::120:266::5:3:4799:1502:4786:::|h[Dribbling Inkpod]|h|r"
-- 72 - fury warrior
"|cffa335ee|Hitem:169319::::::::120:72::5:3:4799:1502:4786:::|h[Dribbling Inkpod]|h|r"

A way would be to cycle through a set of specs that eventually have all the stats, but I don't feel that's the best way. Anyone got a better idea?

Edit: it seems both these links, when parsed on a character, return the same thing, so that's a bust