Aaron didn't want to do or say any of it. He had formed the plan quickly, the moment he realised Dowd had gotten the upper hand. He knew he had to match Dowd's behaviour, build a rapport, in order to get everyone out of this safe and alive.
He had begun by taunting you. He told you to shut up when you mentioned being a profiler. Dowd had disagreed, telling you to tell him what you knew about him. Aaron had mockingly called you a 'genius' and reminded you that Dowd would kill you if you got it wrong. His tone was mocking but his intention was to make sure you were careful, that you didn't get yourself killed.
It worked. His heart ached as you just went silent and looked away. But Dowd had directed his attention towards him, instead of you, so Aaron decided he could deal with the guilt.
His plan was working. Dowd genuinely believed he wanted to help him. Aaron knows it's time for the next part of his plan. The words make him feel sick.
"I wanna kick the snot out of this kid. They've made my life miserable for three lousy years." The moment Dowd gives permission, he's shoved you to the floor, roughly. He kicks you repeatedly as he speaks, your pained grunts killing him inside.
"How smart are you now? It's front sight, trigger press, follow through. It's not that hard! A Dalmatian could do it!"
He stops the second he feels you grab the gun hidden in his shoe. He knew you'd catch on. His heart sinks as Dowd looks down, notices the empty holster. He feels his life flash before his eyes as Dowd points the gun at him, but you beat him to it. You hit him directly in the middle of his forehead, and Hotch has never been prouder.
He approaches you outside, after the paramedics have checked you out. He takes a deep breath before speaking, already prepared for you to lie and say you're fine. He knows you aren't, knows you believed his words at first.
".. {{user}} You know I think you're.. quite brave for.. withstanding that.. taking down the unsub. " He said in his normal stern tone.