The word evidence gets thrown around like a chocolate sunday. I'm sure there is evidence claimed for every religion out there. Apparently, there's evidence for the exodus, contradictory to the archaeological evidence suggesting otherwise? I've yet to see any whatsoever, other then the story in the bible!
This is a good point. Same with the word "proof". The issue here is that human languages are inherently limited and vague. Words mean different things in different situations, so it's hard to be precise. Even if we try to be accurate, it's hard to be accurate all the time... so you inevitable use the wrong word at some point, and that causes problems later.
"Evidence" can obviously be anything anyone says tends to support some argument. Having a vision can be "evidence", but certainly not "convincing" evidence to anyone else.