Opportunistic Spellwork: Say a baker in The Citadel knows a spell to bake bread-- making a hot little magic-oven with his mind to cook the dough. Say he's in a very pressured situation, and he decides to use his mind-oven to scald someone's hands. That’s opportunistic magic, used for another purpose than originally intended.
This takes some real cold planning to perform, and most characters just aren't in the right state of mind to with willful intent harm someone like this. They'll most likely be shaking, trying desperately to concentrate, and even if it works the mere sight of another human being hurt can make the spell fizzle or - at worst - backfire. You don't know how the safety works, and you definitely don't know how many bullets you have.
Casting (Citadel) like this safer than Raw Casting, but still incredibly risky.