Thought it was Dragon at first but the flashback made me think it’s Blackbeard who will do a Rocks parallel that made Imu snap. They tend to take advantage of the chaos and probably knows the Celestial Dragon are starving. Plus, Lafitte knows the in's and out and have Saturn's face who could fool the guards.
I believe Akainu is getting his redemption arc only after he meets Dragon and gets humbled imo. "You are mistaken, you want to know the truth why I left?"... Have seen this trope many times.