That Ysgramoar was a big fat liar. Knight paladin-Gelabor say's that the snow elves, did not infact start the war, they peacefully worshipped the gods, had a advance society, and where friendly to the nords, how did the nords repay this kindness? They claimed that Skyrim was now there home and waged a brutal and genocidal war against the snow elves, turning them into what they are today...This mean's we cant trust nord historians any more. How can we know what's true and what's fake?

As in most things, the history is probably more complex and grey than either side is willing to admit. The Falmer most likely did destroy Saarthal and butcher it's population. Remember, the Nords also say that they lived peacefully with the Falmer. However, not every Falmer is the same and most of them likely had nothing due to with the Night of Tears.

Contradiction, like most parts of history. Not uncommon in TES lore, don't you think? That's simply the Snow Elves' point of view.