Here and there the usage of the words this and that look artbitrary and often completely interchangeably.
Example
Today the politician Pete Brown stated that the CIA bribed the president's advisors. This is of course not true.
The word this in the above sentence should refer to the sentence itself shouldn't it? And the sentence should be more correct if it was "That is of course not true."
Is my observation true? If yes, why is that ("this(?)") often done?
Isn't the word this a self-referential word so that logically, saying This is not true is a contradiction in terms?