The creation kit has the example:

Event OnSpellCast(Form akSpell)  Spell spellCast = akSpell as Spell  if spellCast && spellCast == FireballSpell    Debug.Trace("We just cast a fireball!")  else    Debug.Trace("We cast something, but we don't know what it is")  endIfendEvent

Noting the fragment

  Spell spellCast = akSpell as Spell  if spellCast

Does this part automatically return false if the event was triggered by a potion, enchantment, or ingredient? I'm hoping the answer is 'yes.'

Figured out the solution to my own question: just do a 'hasSpell(akSpell)' and it should work out just fine.