The lesson to be learned here is that you have to apply your own logic to what you you see and hear. Each person must think independently and critically to determine what is the truth.
Just assuming that whatever so and so says and what such and such publishes is the truth is not a reliable way to determine the truth.
Likewise assuming that whatever certain other people or organizations present is always a lie is not the way to go either.

You really can't trust anybody but yourself and your own reasoning.

For example there are reportedly Facebook posts and tweets from Iran that the recently announced deal is not what was reported by the US.

How do you know it is officials from Iran? It could be officials in Iran trying to muddy the water. It could be Israelis. It could be Russians. It could be 12 year olds having "fun". It could be American Iranians who don't want the deal. It could be anybody for any purpose.

You have to exercise your own judgement independently or you may be on the wrong track.
Think for yourself and do not blindly follow the mob.
I myself would love peace in the world.