If Dershowitz isn't taking sides why is he assuming they had the photograph when he doesn't know? Plus this statement that he makes here isn't impartial at all...
"I've had cases in Florida against prosecutors,” Dershowitz said, “and this is not the first time they have willfully omitted exculpatory evidence. It's a continuing problem. Here, it’s not only immoral, but stupid. The whole country is watching. What do they benefit from having half-truths in an affidavit?"

Again he doesn't know if they had the photo but he's already declared the prosecution of being guilty.

Fair play!