I think if you don't have the apps installed they'd probably would assume you were telling the truth. As a white man, you probably don't have much to worry about.
They actually detained him because he didn't have a Visa to be in the US, which is a requirement for anyone, even those who would not normally need a visa, who has been to Iran and a select few other countries in the last few years.
That isn't to say the entire situation wasn't bullshit, just that it wasn't the case of the Borders agent randomly stopping him for being in Iran.
