Harry had conjured a sling for his wand-arm and realized he couldn't really spell well with his left hand. He had the Derringer reloaded with more Conflagration rounds, but felt wary about what kind of future the Aurors would be with these muggle-inspired weapons. And I had to call Code C, Merlin please don't let me regret this. Pain shot through his arm when his friend Ronald tried to clean the wound magically, only for them to learn about Bellatrix's penchant for making cursed wounds almost sentient against being healed.