Cook didn't lie about it at all. People who didn't watch the whole session are taking one line of his out of context, and ignoring the followup that dealt specifically with this issue.
That, of course, is the problem with these open testimony sessions. Legislators get 5 minutes to pursue random agendas, and everyone knows that the sole purpose of the enterprise is to generate sound bites for people to argue about later on. The real fact-finding is done in writing, and by staffers, not legislators themselves.
That's not always true; sometimes the Q/A periods are used to establish an evidentiary record, unless that falls under your definition of 'sound bite'. The chance to ask unrehearsed questions of a tech company CEO who has to answer on the spot is valuable, even if seldom used to its full potential.
I'd be very surprised if Tim Cook lied in his testimony. Politicians seem to have a major problem with big tech,. They just don't understand any of this and hopefully they don't make the same mistakes they made with Bell, that basically fragmented the OS stack and caused more problems than it solved.
Uh, just be certain that the congresspeople already knew the answers to each question before they asked it and the purpose was to be able to tick a box saying "..and even in light of these FACTS, the company denied it on 7/30/2020 before this Committee" thus making it easier to condemn them and garner support for remedies/penalties already under consideration.
I'm pretty sure these hearing are almost entirely theater and there's basically no chance Tim Cook gets personally charged with a crime. But, these statements can have large second and third order effects. The worse the tech CEOs and their companies look, the more political will there will be for passing significant legislation that affects them.
They are under oath with the potential for a perjury charge if they are caught knowingly misleading the lawmakers asking them questions.... The only reason that people such as those who were speaking yesterday would ever "correct" themselves.