Logic of Tycho's accusations

i just want to know In the Kyrtos trap when Corran is talking to Urlor and Jan in Lusankya about Tycho being a sleeper agent, Jan says "I thought he was [a sleeper] but that all must have been an act. If you think about it, being a sleeper many people would speak in front of him When he recovered he'd have folks trying to help him with his memory."
"When he got to the point where he should have been better they pulled him out and debriefed him. He had me fooled."

Corran then agree's with him.

I'm confused. What exactly does that mean? i find it unclear. Whats their logic here, i never quite understood what it was yet, is the basis of Tycho's accusations him bein a sleeper agent? i know soem people disagree, and think he is a normal traitor, but i don't know why they think what they do

 

Tycho is innocent, don't worry about it.

 

I think the idea was that Tycho just slept as a result of everything they put him through and as a result were unable to brainwash him.

Others like Jan and Corran could not be brainwashed but stayed awake when jailed in Lusankya's belly

And other were turned like Isella's husband was.

Tycho was sent back by Isard with her knowing full well he would never be trusted again and this helped her as it took 1 top alliance fighter out of the equation.