> unless I can prove in court they fucked up my shifter, I have to take down my 1 star review or else they'll sue me for damages ...
Heh Heh Heh
So, how feasible would it be to change your one star review, so that it basically says "I'm giving them one star due to this threatening legal letter they sent me"... and include a scan of the entire letter as the attached / supporting image?
Doing that, you've ceased claiming they damaged anything. Instead the letter they provided is the whole reason. And it will give future reviewers a warning ahead of time.
It would be kind of surprising if they then tried to say "we never sent such a letter...", in which case you can put your original review back online. ;)