Here's the part that I do not find credible at all.
I've also discussed this before.
"Police brought Zimmerman into the station for questioning for a few hours on the night of the shooting, said Zimmerman's attorney, despite his request for medical attention first."
I find this HIGHLY suspect. He was treated at the scene. If he was hurt that bad, he shouldn't have signed the paperwork that the paramedics would have HAD him sign. It's called a "Patient refusal". It's basically saying that the FD suggested that he be treated at a local hospital, and he declined.
I'm sorry, I call BS. So, i'll take the rest of the article with a truck load of salt, just as you suggested.