That person's testimony would be challenged, just as you are doing now, the accused would swear  that it never happened, and everyone could believe who they wanted. Thus the need to encourage people to get proof in the form of a recording.

I went looking for the link to a couple of videos I posted a few weeks ago showing a meeting of (mostly "brown") citizens with their liberal MP about their concerns about M-103, because there was a woman who expressed her fears as a non-practicing Muslim about being threatened by condemnations by imams in mosques for her apostasy, asking what she could do about it. 

Guess what? The videos were removed...