Even if the canonical copy were hosted on the Council's website, you would still be trusting the hosting provider, the DNS system, and the certificate authority - all private entities.

What is needed is cryptographic authentication so that the git servers can be completely untrusted. This is also necessary to comply with the Uniform Electronic Legal Material Act (adopted by DC here: https://code.dccouncil.us/dc/council/code/titles/2/chapters/...). We will be rolling out such a system based on TUF in Q1 2019.