You tried to use your knife, but even though it's designed for throwing and thus thinner than most blades, it's still too big to fit into the keyhole. You would try to shimmy and wedge it further, but soon you'll notice some metal from the lock getting shaved off and stop. Wouldn't want to accidentally jam the lock. You could try and use your hairpin, not that it's much better. Combined with your inexperience and improvised tools, you're not sure if this would be much better. Jackson was still here, watching the door while occasionally looking at you, as if he's on watch.