Go to 4:24 and turn the volume up to hear what Acosta accused the Administration of doing, and then listen to what Miller said. Acosta was out of line making such an inflammatory accusation. What Miller said in response was correct. I watched it occur live, and watched it again on the video below, just to make sure what I thought I heard Acosta say was in fact what Acosta said.
Now, right or wrong, should Miller have said what he said? IMHO, no. It was unprofessional to do so. I would have handled it something like this - 1) As soon as Acosta made that statement, I would stopped talking, stared at him for about 5 to 10 seconds without talking, moving, or even blinking if I could control it, then turned my head and called on someone else, ignoring Acosta from that point forward. 2) As soon as I got off the podium, I would have had an aid write a note to be delivered to Acosta as soon as the press briefing had concluded, to have him meet me in the White House Counsel's office immediately, at which time I would have closed the door when he entered and laid into him in private, with the exception of the White House Counsel being present to keep me out of trouble. Oh, and 3), I would have made a recommendation that Acosta lose his front row seat in the press room, at least for a while.
Now, what needs to happen, is that Miller should never be allowed to stand behind any podium in front of any gathering of the press, not even a high school newspaper reporters meeting.
Next, Acosta still needs to be talked to, off the record, and in no uncertain terms regarding the decorum of questions asked in the White House press room on live TV and that those questions should not be accusations of the inflammatory type that he made. If Acosta thinks that such accusations are appropriate, then move his butt to the back of the room and never call on him again.