Yea, he did look off, but Zimmerman has already said he got on top. Check Zimmerman accounts of events Section
Shooting of Trayvon Martin - Wikipedia, the free encyclopedia
As per the link above:
When Zimmerman tried to move off the concrete, Martin saw his gun and said "You're going to die tonight motherfukker!" Martin grabbed for the gun, but Zimmerman grabbed it first. He said after firing his weapon at Martin, he wasn't sure at first that he had hit him
, so he got on top of him in order to subdue him.[191][193][197][dead link] Bystanders and police arrived shortly after Martin was shot.[198][199]
so this might be confirming his accounts of what happened.