Please look at those two screenshots of firefox opening the same static file with and without librejs enabled.
They are rendered in the same way in both cases, but when you look under the hood, in the network tab, you can see that with LibreJS enabled, the response it "got from the server" misteriously gets a <html>, a <head> and a <body> elements - which just don't exist on the original file.
This may not be a problem if you're opening the files on the browser like I did on the screenshots, but it breaks when you load those files inside ajax calls and use them as AngularJS templates.
I think librejs shouldn't be allowed to change contents like that.