There are so many phoney news web sites out there now that it’s easy to get taken in by them now and again. If you get caught out then you really should throw up your hands and admit you were wrong. 

It’s not good enough to say “but it’s something that might have been said or done by that person” because that doesn’t make a better web.

Don’t repeat something without research just because it backs up your political/world view. There’s nothing weak about admitting your mistakes and in the end perhaps these sites wouldn’t get the publicity they need to spread their garbage all over social media.