I'm going to try to keep this very vague and unidentifiable.
In the course of my job, I found that within a project there were indications that things could be going wrong. Several staff members had observed potential red flags but failed to investigate or escalate any concerns. (It was a comfortable long-term project that had run smoothly for ages so perhaps the team had become a bit complacent.) I was transparent with my co-workers about what I had noticed and that I felt we were all going to be pulled up on it.
In my regular review meeting, I discussed that project with a line manager, as well as all my other current work.
Later, management scheduled individual meetings with some of the people who had worked on the project.
Afterwards one of my colleagues (X) approached me angry and asked why I had had thrown him under a bus. He said he was told that I had sought my line manager out and reported X in particular for breach of policy and he was going to be disciplined.
I always got on well with X, and I was really upset at the idea of people being told I was making accusations. I hadn't, I was pointing out where all of us could have done a better job. I hadn't assumed there was any intentional wrongdoing.
I wondered if I hadn't expressed myself properly or if my concerns had been misrepresented and X took the brunt of it. So I asked to meet with the manager.
And it was bullshit. X was never told that I had reported him or that there was breach of policy. X was mad about being questioned about the project and apparently wanted me to be angry at my line manager. And I assume he wanted the rest of the team mad at me for dobbing him in.
So I guess my ultimate question is, can a person really just go around telling everyone that I wrongfully reported him and to watch their backs around me?