Martha Stewart went to prison for lying to the government even when not under oath - and so have countless other people. This is now standard operating procedure for law enforcement, as it's much easier to catch a person in a random (and possibly unintentional) lie than to prove a real crime.

No, it is much more nuanced than that. Giving false information is not the same as lying. With perjury, you have to willingly lie or give misinformation. On purpose.

Being honest about not being able to answer a question in an open forum isn't perjury. That is someone trying to follow conflicting laws and erring on the side of caution. If his information was bad and he wasn't aware at the time, it isn't perjury. Misremember but try to answer? Not perjury.