Doubtless the fault lies with the Iranian government.
But the Foreign Secretary is meant to be our top diplomat, aren't they? They are expected to understand that negotiations with foreign governments are meant to be nuanced, not "They're wrong and we're right"? Even if you think that?
When Johnson said what he did it gave them the excuse. None of us have any idea what happened to Nazanin in prison, do you not think that the Iranians told her what Johnson said, and told her that they'd been right all along? Do you not think she felt abandoned by the government? In all likelihood Iran used the statement from Johnson to show their own people that they had been right all along. They used it in the negotiations. They used it to convince other countries that were siding with them that they'd been right all along.
It seems that some contributors to Social Media sites have a better grasp of foreign relations than our former Foreign Secretary.
Army horses loose on London streets
Last weekend, in Rutland, the first statue in Britain of the late Elizabeth II was unveiled.