They said it was hacked. That lie was all over the news. They actually tweeted that their account was hacked!
You are correct. The CO GOP spokesperson’s statement said this: “The last tweet was the result of unauthorized access to our account and in no way represents the opinion of the party. We are investigating.”
It seems to me, though, that any difference between “unauthorized access” and “hacking” exists only a strict, definitional sense as to the method used to gain access. The fact they didn’t use the word hacker is actually pretty interesting. Suggests they have more than a hunch where it came from, and it’s a little too close to home. All hackers are unauthorized users. But not all unauthorized users are hackers.