No; Musk has demonstrated with his actions that he is a liar and his word means little. You could look at his “taking Tesla private at $420; funding secured” tweet, or his late SEC filing for his large ownership stake in Twitter where he claimed to be a passive investor days before making this offer, or any number of prior examples. If you assume good faith from Musk at this point, you are a fool.

Musk has lied repeatedly in public, so it's difficult to assume good faith from him.

That's not what "bad faith" means. If GP didn't care if their statement were true but just said it to make Musk look bad, then it would be in bad faith.

Musk has been very publicly coy about his intentions for several months, so it's hard not to have an opinion at this point. Just because that opinion may be wrong doesn't mean it's offered in bad faith.