Exactly...
"Did you have a conversation with Dir. Comey about his conversations with President Trump?"
"I'll let Dir. Comey speak for himself tomorrow"
But why cant you answer it if you were part of a conversation with him?
If you're ever put in any situation similar to the one they're in you don't ever want to answer a question that you don't have to even if you really have nothing to hide. Because once you commit to an answer all they have to do is find ways to discredit it.
I understand the frustration, but these dudes know EXACTLY how this game works and they ain't falling for it.
Edit: Just like when they asked if anyone took notes. If you answer "yes", they'll automatically subpoena them and any other related documents. If you answer "No" and they find out you did well, you fukked up.
But if you just say "I won't answer that." then they got nothing on you even if you did or didn't.