Call me an overanlyzer - but I don't think any of the three survived the encounter.

I don't think anyone's disputing that Cleary bought it when he fell on his own knife; so I'll move on.

Next, I know it unlikely to kill from a single blow - but that the wife is still unconscious a half-mile's walk (stagger?) later, and that I don't think body temperature drops drastically from being knocked out; I think Cleary managed to end her life. That the speaker refuses to accept that she is dead is, I think, a reasonable response to the sudden and violent loss of a loved one.

Lastly, after Cleary pulled the knife he struck the speaker a blow that brought him to the ground and covered him in blood. I think that wound was a deadly one.

When the speaker meets Harris, coming up on a cart with a horse... I think Harris passed away long ago, maybe went to war when the speaker stayed home and died in the fighting; come as an agent of Death to collect the Speaker as he bleeds out. It seems to me that Stan puts an awful lot of nostalgia on that first line, yon trap and that old mare.

That is, if the speaker even left the room. Perhaps the people in the bar never lifted a hand to help him out because the rest of the scene after his fight with Cleary could have been a hallucination brought about by loss of blood.

At least; it's this line of interpretation that sent the chills up and down my spine and made me again terribly sorry that I'll never have a chance to see Stan live in concert.