no offense, but it is extremely common for an interviewing officer to refuse an applicant to their face- I have come across dozens of such cases.
if officer is in a friendly mood, they will not give any indication and will issue a refusal post interview.
No offense taken. I wasn't clear, I wasn't claiming they do not do this - I consider it an odd practice on IRCC officers' part because it introduces potential issues (in my view) from IRCC perspective.