From the first article I found on the matter:

The musician was invited by Russia to address the UN Security Council.

He called for a ceasefire and condemned Russia's "illegal" invasion, but also denounced "provocateurs" in the West who he claimed were responsible.

Ukrainian ambassador Sergiy Kyslytsya called Waters' speech "another brick in the wall" of Russian disinformation.

Yeah, either he got played or got paid, I think. But well, the people in media are not somehow godlike and not guaranteed to be correct always. If anything, that would be a cognitive bias to think so