TRAVON WOULD HAVE GONE INTANTLY NON VERBAL

 When GZ's bullet slammed into Trayvon's chest,  chewing up his left ventricle and puncturing his lung,  he experienced quite a bit of trauma.  Massive chest pains,  lungs filling with blood,  a chest cavity filling with blood and a brain starving for oxygen,  rising CO2 levels causing urgent signals to breath,  it's difficult, if not impossible to imagine TM's dire internal struggles from keeping him non-verbal. 

Okay,  but if that wasn't enough to prevent him from uttering a coherent phrase,  then this certainly would.  You see,  to operate the lungs the diaphragm needs an intact plural cavity,  otherwise,  breathing in or out is impossible.  Trayvon's chest had a hole in it,  so any attempt to compress the chest does not force air out of the lungs,  but,  instead releases the pressure through the hole in his chest.  Any attempt to draw air into the lungs,   again,  doesn't create a vacuum in which the lungs can expand,  but instead draws air in through the hole in the chest that defeats the creation of the vacuum needed to inflate the lungs.

So,  Trayvon would not have been able to move air in or out of his lungs,  once the hole in his chest was opened.  Which is indicated by the earliest attempts at CPR,  the gurgling noises were air moving in and out of the chest cavity,  without effect on the lungs.   

So,  Trayvon did not fall silent for lack of air in his lungs as some medical people have explained.  He would have had some residual air in his lungs.  What Trayvon lacked was any means to move that air in or out of his lungs,  because the hole in his chest defeated the compression/vacuum action of the chest and diaphragm.