[anonbanker]

The short answer: because his written response, and the committee's acceptance of his written response, absolved him of any criminal wrongdoing caused by his testimony.

A little known fact: under UCC and UNCITRAL, you have 72 hours to modify any contracts you make in court via private correspondence. With 3 days to receive, and 3 days to send a response (and one day for a Sunday) tacked on. If the other party goes silent afterwards (as the committee did), clapper can use that silence as tacit acquiescence to his modified statements. In this case, the senate committee accepted that "least untruthful" was considered sufficient reason to make false public statements. Clapper brought that private agreement public via the press, and now it's nicely cemented in stone, as a valid process that anyone else can use in case they're ever caught lying to congress.

Someone really should be teaching Ed Snowden contract and trade law. I bet he'd pick it up rather quickly, and it'd make his current situation easier to deal with.