Well it isn’t like he had a chance of killing a full hp Hog anyway.
I duel hogs as cree all the time…
70% of the time, i stand a fair chance of walking away from the fight.
572 health is not a full health Hog. McCree can totally do that with masterful jukes and a pinch of pocket sand.
And quick reflexes…
Those must of been some professionally terrible Hogs. Or maybe you’re secretly a top500 Mccree! 
Nah… Just been playing him since launch.
Often times they fully expect you to save flashbang for when you see them start to heal, so if done correctly… you can surprise and disorient them by using it to interrupt their next reload, after you dodge the first few shots, depending on how many they have left by the time you fully instigate the fight.
Then, all you need is to chain a few headshots.
They never see it coming.
And if you use your combat roll to both dodge the last couple of shots, and to cancel your flash animation/reload, You have the ammo advantage.
I do love chess… Even the kind with guns. 
(Brain slowly melting… that’s all the math i can do for today…)
The person might have a potato audio setup and had no idea Hog was right behind. Alternatively, they might have been experiencing the recent major audio bug issues plaguing a lot of players.
Or, who knows, they might have been plastered, wasted or zoned out. It happens.
For the title, I was somehow expecting more. 