> something ... is only reported in RT and not in any other major new source

And this is an appeal to numbers (http://www.nizkor.org/features/fallacies/appeal-to-popularit...)...

You may be right, but your logic is fallacious. If there's only one news source and that news source is biased, then it doesn't follow that anything they say is untrue.

You are calling something false based on the source. This is simply illogical: a broken clock is right twice a day. Following your reasoning it would be wrong even when right.

Either the news is true or it isn't. Judge it based on its own merits, not from its source.