Connor had known one emotion for certain in his life. That emotion was fear. Fear of the environment he didn't know, fear of the humans with heavy boots and heavier guns, fear of having no cover while he was injured, fear of the look in his own eyes as he did micro calculations to weave around bullets without faltering, fear of his own eyes being turned on innocent people that couldn't defend themselves, fear of never getting to live, fear of what came after he flexed his finger on the trigger. But that was not his fear, that was the fear a PL600 choked him with to keep him from finding Jericho.
His own fear came after. His fear came in the fraction of infinity, in a void with no sight or touch or ground. For a second, he was nothing and nowhere, no one would find him, he could not leave, all that was there was him and his constant string of thoughts bouncing off each other with nowhere else to go.
Connor could not handle not being, that's why they programmed a zen garden for him to explore every stasis, that's why they gave him Amanda to talk to him when no one else would. Connor was made to think, Connor thinks therefore he must be. Not being yet left to think would bring anything to insanity - instability.
So staring up at the deviant that showed Connor fear, unequivocally and undeniably, made Connor's hackles raise. Even hung up on an evidence shelf, the PL600 made Connor keep reevaluating the danger over and over.