You did not question the Prime Minister. You said you looked at the information available. In your opinion, it was enough to decide not to go any further. I am not a police officer, but in the end, among the four people you questioned, the key people you should have met with were not included.
Evidence of meeting #105 for Access to Information, Privacy and Ethics in the 44th Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was investigation.
A recording is available from Parliament.