Just the way it was handled tells you something is wrong. When 85% of a country's population votes using paper ballots - and the result was announced a mere 2 hours after the polls closed, something is wrong.
How the heck do you process millions of paper ballots in two hours? You don't. So it's obvious that the true story is that the conservative religious types running Iran have had a sham election that has a lot of Iranians hopping mad. And it's a shame. Change was in the air and the people were ready for it, just like in the U.S. in 2008. But nothing scares religious hardliners more than change.
Change is pretty easy to prevent when you have all the guns and media and the means to silence communication and don't give a shit what your own people or the rest of the world thinks.