If he sells now he can potentially buy back with a warrant attached from Tranche 4 if one is in the works, and probably pick up a nice capital loss to write off against any future gains as well. If i'm not mistaken he picked up his shares at around the $1.00 mark thru the Denselight purchase.
We do not know his credit history, perhaps he can't get a line of credit.
Just my 2 bits,
Cheers