This is a match Down manager Eamonn Burns will want to forget about quickly, especially if he finds himself in trouble after tempers frayed at half-time.
The Mourne boss locked horns with a Cavan mentor, and referee Padraig O'Sullivan, who was attempting to intervene, appeared to be unintentionally struck by an errant hand from somewhere in the midst of what Burns termed "handbags".
The ref spoke to Burns and the latter did not take his place on the sideline for the second half.
By that stage, Down were in front by 0-7 to 0-6 and in truth they probably should have got something here. They carved out several goal chances but couldn't capitalise while Cavan reeled off a number of high quality scores on the home stretch.
"I think we shot 37 times and the return wasn't high enough. I thought we played well for long periods in that game," Burns remarked.
"We created three or four goal chances and when Shay Millar got hurt we were straight through and he blew the game up. I don't know what the total definition of that rule is but there was no advantage to us.
"That's very disappointing. It would have been one on one and you'd expect Donal to score."
O'Hare and Man of the Match McKiernan both pointed before Down drew level with points from Caolan Mooney, Kevin McKernan and Ruairi Wells.
Entering the tension-filled final minutes, there was nothing between them but Cavan would out-score their opponents by 0-4 to 0-1 when it mattered most through Sean Johnston, McVeety and a Galligan 45.
Cavan: R Galligan (0-1, 45), J McLoughlin, P Faulkner, Conor Brady, M Reilly, Ciaran Brady, E Flanagan, S Murray, B Magee (0-1f), D McVeety (0-1), C Moynagh(0-1f), O Kiernan (0-1f), N Clerkin, G McKiernan (0-4), C O'Reilly (0-3, 2f)
Subs: C Mackey (0-2) for Conor Brady (25 mins), A Cole for Clerkin (h/t), C Bradley (0-2) for Moynagh (45), S Johnston (0-1) for Flanagan (65), K Clarke for Murray (68)
Down: M Reid, C Flanagan, B McArdle, A Doherty (0-2f), R Wells (0-1), N McParland, C Mooney (0-1), P Turley, N Donnelly, C Francis, C Maginn, S Millar (0-1), C Harrison (0-3, 1f), D O'Hare (0-4, 3f), R Johnston (0-1)
Subs: K McKernan (0-1) for Francis (45), D McKibbin for Millar (57), C Poland for Donnelly, R Millar for O'Hare (68)
Ref: P O'Sullivan (Kerry)