Sen. Wyden is on said Committee, and asked Clapper a question that, in Clapper's own words, he answered with a "least untruth" statement that was "too cute by half". This can be roughly translated as "a baldfaced lie".

Apart from that, I am personally unaware of any instances where DNI Clapper has publicly lied.

Additionally, DNI Clapper appears to only answer prepared questions (i.e. forwarded to his office prior to the discussion). I'm not sure if this is standard protocol for Congress, and for obvious reasons I also don't know if this applies to private briefings.