It's not mental gymnastics in the slightest. Did the Foreign minister and Speaker of the Parliament, the official representatives of Iran, declare the straight "completely open" or not? The president is simply stating that the blockade of Iranian ports will only be lifted when the handshake deal is formalized in ink. It's called a backstop. It happens all the time in negotiations, big and small.

You can try to claim this is part of some game on the part of the Iranians if you want, but you can't accuse the president of "lying" when the official representatives of the other side are formally validating the critical parts of what he is saying in public. That' s just bias coming screaming through.

Again, IMO it is far more likely that there are two competing factions within the Iranian government, and the IRGC is (in their minds) putting a capital "G" in IRGC. Almost a "over my dead body" kind of thing (maybe literally...)

This is far from over, from either perspective. Claims of 'this is over' are just as ridiculous as those who claim the sky is (inevitably) falling. There is a lot of baseball left to play...