This does not always work. Not necessarily "hearsay", but there was a coworker of mine who would happily take credit for everyone elses work by sending emails i

This does not always work. Not necessarily "hearsay", but there was a coworker of mine who would happily take credit for everyone elses work by sending emails in a timely manner (people tell them stuff they work on, then you'd see an email from them pretending they lead the effort and it was their idea). Many times this got escalated, the manager didn't care. Everytime someone talked to that problematic person, it was "the first time he heard about it".