I read that the defense had 10 strikes, no questions asked, and then 2 more if needed. Perhaps they had used their strikes up before this guy came along, or maybe he misrepresented himself in the beginning.
Rainy - there is a difference between peremptory strikes and challenges for cause. Peremptory strikes can be used for any reason - or no reason at all. A challenge for cause is based upon legal cause. Knowing parties or witnesses such that your opinion of their testimony may be bolstered, or undermined, can be such legal cause. There is no numerical limit on challenges for cause.