It says quite clearly that you a) believe copyright belongs to the company, b) want him to give all access to infrastructure, c) revoke his access to Copperhead branding.
What exactly have I got wrong or over-simplified?
(Also I think it's super weird for you to use HN as a forum to push this dispute.)
It seems possible one of them is a bad egg. Or perhaps they have just had a very bad falling out. It does appear to be the case that because one guy is a/the coder, everyone is being more sympathetic to him. I haven't chosen a side yet - and I'm still reading through everything.
Hopefully this gets resolved and after it the bad egg (if one exists) leaves the company.