If he talks against the advice of legal counsel, he would be digging a hole. In many departments, the officer will have a legal representative show up at the scene. One of the things the rep may do is to advise the officer not to make a public statement. Plus, the lawyers defending the Ferguson police in the lawsuits will also tell him not to make public statements.
We saw how hard it was to unravel the Trayvon Martin case after the media spread false information for weeks.