It's not eavesdropping when you're invited into the conversation

This has been...puzzling (?) me all day. Pierre Poilievre did a radio interview this morning where he insisted that Gerry Ritz was the victim of someone eavesdropping on a private conversation, when the Tory who recorded the NDP caucus call yesterday was a whistleblower.

Let's see...whoever leaked the story about Ritz making listeriosis jokes was a staffer on a daily briefing call. There were 30 scientists and communications staffers involved in those calls. That doesn't sound like eavesdropping on a private call to me. Also, aren't whistleblowers generally less powerful than the person on whom they blow the whistle? Or maybe it's the reverse - that whistles are blown on those in power. Either way, I don't think either example fits.