You don't have to, there are people who get paid to look over videos and pictures to determine the legitimacy of them. It would take a few days max to have yourself cleared of any wrong. Photo editing has been a thing for years now and it's never been an issue because of how easy it is to disprove, why are people making a big deal out of this?
No, that's very much the definition of fake
noun
1.
a thing that is not genuine; a forgery or sham.