My understanding that in a domestic abuse case only a judge can take firearms away and to that, you have to be charged. Could be wrong or there is something else to this story that we don't know.
My point of view coming from a LE family, it is usually a bad idea to take a gun away from a cop and then let it be known. While killing a cop or shooting at one is a bad idea for an extended llife span (I was in Lakeland, FL last Sept. when the deputy and his dog were killed and another police officer was wounded), for the most part bad guys don't care about killing cops. In fact, some wear it as a badge.