Okay, I'll recommend he temporarially discontinue the use of the simulator. I have taught him loops, rolls, hammerheads, and figure eights in attempt to let his fingers loosen. I also taught the figure eights to aid in orientation since a properly executed figure eight will have the student controlling the aircraft at almost any angle. He's not ready for inverted flight yet. I have been talking him through things. I always show absolute confidence because I am confident, but more importantly, it puts the student's mind at ease. He still tends to tense up midway through the flight. When I see this I have him look away from the airplane (while I control it) and do shoulder rolls or something to loosen up. I give a debrief after every flight. I think the simulator may be the link causing the chain to break between formal instruction.