The "hey that's up to the investor and his law firm" part is a negotiating tactic where you appeal to lack of authority (I forgot its real name). It's bullshit. They're the founders. They can make things happen. Do you think if they would say this to Richard Stallman? No. They're just pretending something's impossible so they don't have to give in in negotiations.
On a final note: Everyone here is going to give you advice that, on the whole, is aggressive. "Tell them to fuck themselves." "Sabotage them." They're saying stuff that amounts to "You go, girlfriend! Tell that man he ain't good enough for you!" and they're not necessarily the best course of action. Especially when a recession looms.
I've been doing work on their servers and checking it into their repository I'm not sure what that means. Up here in the north east where there isn't a large pool of investors / firms like silicon valley I feel pressure to comply so this investor doesn't vanish.
You obviously have them by the balls. The fact you've touched a server and even operated it tells me you're probably a nerd, like myself and everyone on this site. You don't really have a lot of experience with this sort of thing because you probably had no social currency growing up. Now you have a lot of currency. Enough to kill their startup. If you can't work up the courage (not a trivial process) have someone negotiate on your behalf. Alternatively, move to another startup, or to California. You're technical. You can find something better.
As always, I am not a lawyer.