I've racked up a lot more time in crucible than any other aspect of this game and I can honestly say I've never been tbagged by anyone with skill. It's always people who fist of panic or nova bomb and are lucky enough to get a kill or tag you when you've just finished a firefight with someone else, I check their score at the end of the game and no tbag has ever touched my guardians face that came from a positive KD player