Insist on a walk through on your last day with their representative. Take video. If they refuse, note that. And take video of the place anyway. Show everything. Make sure they have your new address. Print this https://www.dcregs.dc.gov/Common/DCMR/RuleList.aspx?DownloadFile=F072555F-0000-C93C-AA3B-E0DC116B10AA and leave it sitting in the middle of the room. (If you really want to flex) they’re bluffing, they won’t actually sue you for it, because they can’t. And if you leave the place in reasonable condition, you’ll get your deposit back, too.