To be fair, Clapper did come back for a follow up, and basically said, "oops, looks like I was wrong." That's it. Congress didn't push back, and thanked him for his service. So looks like Congress is complicit as well.
Clapper was forced to issue a retraction after Snowden leaked material showing he perjured himself. He defended his then answer as the “least untruthful answer” he could give, maybe that’s a term of art in intelligence when you intentionally suborn oversight.
