always happy to share! The majority of my headcanons on Hennessey’s reasons for what he does are here: http://flintsredhair.tumblr.com/post/151811259762/so-can-we-talk-about-admiral-hennessey-for-a
The gist of them, though, is that I genuinely do not think that Hennessey actually wanted to do what he did. I can’t reconcile his behavior in the tavern scene or his behavior five seconds before he walks into his office with his behavior immediately after, and the difference appears to be Alfred Hamilton’s presence. I think he knew long before Alfred told him that James was not straight, and I don’t think he actually gave much of a shit about that, although I don’t think he approved of James’ relationship with Thomas for quite another reason – namely that he knew he couldn’t protect him if it all went sideways the way it did.
I realize no one has to agree with my weird theory about this, but I think Hennessey did what he did in large part because he couldn’t just be James’ father figure/mentor in that moment – he had to be a commander in charge of a lot of men, and if Alfred found him to be breaking the law and defending gay men, there wouldn’t be anybody in the entire Navy safe from the accusation. Alfred stood poised to either be rid of his troublesome son and his lover, or to do that and to take control of every Admiral, every Captain, every officer of any rank that didn’t want to be accused and hanged, gay or not. I really think that Hennessey did what he did because he had to get James out of London if possible while still protecting his men and he did that, at a terrible cost.
Not saying that I don’t understand other people’s reasons for disliking him, though. I’m extrapolating a lot, but I think it’s a reasonable speculation that the man that James looked up to so much might have been made of different stuff than Alfred Hamilton.