Nothing is announced in the judging tent. The winners are announced in the awards ceremony, some hours after judging has ended. And some contests its 1 thru 3, others 1 thru 5, and others 1 thru 10, etc..
Grand and Reserve Champion is determined (in KCBS and FBA) by total points in the 4 categories, so its not based on the placement in each category. So the answer to your question is yes.