2. You have no right to challenge someone without providing evidence where the person's information is wrong. The burden of proof is on you.

A very bad rule - also a person stating something must be able to document it - or quote from where he derived his or her opinion.
Both sides should have equal responsibility in case they are asked to provide it and then quote in an accademical way if possible, author, title of the book, essay, place of being published, year and page.