It’s how trials go in this realm. They say what you did, you say why you didn’t, they choose. It’s crude, but that’s been consistent.

After he said, “I deny it!” He again is charged with treason against Ned Stark, Catelynn Stark, and Sansa Stark. He is accused with conspiring against the Lannisters to start a war. All of which he doesn’t deny. What about anything he said was convincing? If the Knight’s of the Vale protect LF at trial, they declare war on the North. LF asked for their protection to which Royce, the second highest ranking person there says, “I think not.” If you were a knight of the vale, do you go against House Stark and House Royce to protect a guy that married a crazy lady a few months ago that is fumbling at a trial? Of course not. He was Lord Protector but not an Arryn so they would not follow him blindly and he did not have the power to declare war.

Yes, LF made a mistake. But only because he didn’t realize there was a player that could see and hear all events in history. How does he foresee a 3ER jumping into the mix? How does a person that relies entirely on sneaking around and manipulating people scheme against one that sees and hears everything? Keep in mind that LF almost succeeded in getting Sansa to turn on Arya. It was a decent plan. Get Arya out, then manipulate Sansa to distrust Bran and his motives. But switching to target Bran and convincing both Sansa and Arya to distrust Bran’s “evidence” is a much harder and riskier task.

Seems to me, LF’s correct move in hindsight (had he discovered that Bran can see and hear absolutely everything from an obscure comment which is a huge leap in logic), was to flee and appeal to Cersei and help her scheme. That’s if he ever got there.