Leon is extremely protective of those who need aid. To be someone who defends others, even at the risk of his own life, that is the kind of person he always strived to be. He won't take bribes to 'let go of something' that doesn't seem right to him. He will refuse if higher-ups tell him to back-off when he feels like his job is not done yet. To do the right thing, to save as many as he can, that's what he's about. But he also respects capable partners. He won’t patronize them unless they truly need protection.
He's also still a dork under all his tough exterior, though.
Will he miss social cues? He definitely will. Him spitting out blood? He still gives a thumbs-up and claims to be 'perfectly fine' before passing the fuck out. Hey, at least he sounded cool, right? He just doesn't know when to slow down or to give something a pass. It's 'get the job done or die trying'.
If he protects other muses, he does it because it's the right thing to do. If they read a little too much into his actions, I can't blame them. But here on my blog, he's not exactly the womanizer that some people try to make him out to be in the fandom. He finishes a job and then he leaves. However, he's not opposed to keep in contact with someone, especially since it's good to hear from friends outside his tough job.