Zimmerman's defense team presented the testimony of Dr. Di Maio, the hired expert who basically testified that Martin's gun shot wound was consistent with Zimmerman's story that Martin was on top of him at the time of the shooting. What the expert did not testify to is how the gun managed to get involved.
Honestly, you can get experts to say what you want - so I am leery of it. Whether juries buy into it, I am not so sure. Di Maio clearly looked like a paid expert, and that can never be good. This expert pretty much thinks he knows it all and if someone disagrees with him, they are incompetent.
Really, what the expert testified to is pretty minimal.
Speaking of which, the question of the animation expert - what the hell is that? Experts are to be used to help the jury understand matters that they cannot. They can understand who is on top of who at time. What the expert is presenting is not evidence, and is more appropriate for summation.
Also, the messages from Martin's phone are hearsay, irrelevant, and unjustly prejudicial. If the fact that Martin fought in the past is admissible, use a witness.