So I'm guessing that the answer is not as simple as I thought. That makes me feel a bit better, I think.
I'll be switching my scripts to something like:
if player.GetItemUsed 1stItem == 1
Do Cool Stuff 1
if player.GetItemUsed 2ndtItem == 1
Do Cool Stuff 1
if player.GetItemUsed 3rdItem == 1
Do Cool Stuff 2
if player.GetItemUsed 4thItem == 1
Do Cool Stuff 2
That should work.