This is specious, and exposes deep naiveté about the law as well as protocol at hearings. The director was put into the position of either lying to Congress or disclosing state secrets. Insofar as the law is concerned, exposing state secrets is a far worse offense. That's just the way it works, and if you don't like it, this particular instance isn't the moment to get into a pissing contest about what public policies you don't like, and all the dumb secrets the government keeps from us, but insists we keep on paying for. You should have been more proactive a long time before this, because this moment was being set up over a decade before it happened in public.
Clapper lying is an inevitable outcome of a hyper-survellience state, which is an inevitable outcome of a servile and paranoid society. The senator should not have asked the question in an open session if the idea was to get an honest answer. If you're a senator on the intel committee, you ask this sort of question in an open session if you're trying to make a public case that we have too many secrets.
And that's exactly what that whole sequence exposes, but per usual, someone from the ignorant mass wants to hang a single person out to dry for the decisions society has made.