"You're not probin' me again!"
"You know they know!"
"They're all around us!"
"They're watchin' us!"
"They know!"
"Gotta keep movin'..."
"Who are you?!"
"He's one of THEM!!!"
"You can't steal my mind!"
"Green blooded abomination!"
"Act like nothing happened..."
"I know things..."
"Get away from me!"
"Don't touch ME!"
"I'm watchin you man..."
"Can't let them take me again!"
"Back off now!"
"In my head!!!"
"Alien are talking to me on my car radio"
"For earth, man!"
"Is on of them" (probably means CJ)

Push him around = talks
Push him around for a long time = talks and tries to fight you
Push him around for a long time = talks and runs away
Shoot a stray bullet = nothing
Shoot another stray bullet = runs away
Shoot yet another stray bullet = tries to fight you
Punch him = tries to fight back
Punch him again = runs away
Punch him yet another time = nothing, just keeps walking

When dead, he sometimes disappears much quicklier than other peds