You're not going to be able to balance the light flickering on the person without a huge amount of work. I would suggest reshooting. If reshooting isn't possible, try replacing the screen (tons of tutorials on screen replacement out there, a quick search should turn them up) and just living with the flickering light on the person.
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.