Raylan goes down in an old-fashioned gun fight, but lives because the bullet went through the top of his hat and just grazed his head. Meanwhile, he killed the gunslinger who drew on him - not Boyd, who was never as fast as Raylan with a gun.
Indeed, Boyd had earlier declined to draw on Raylan, when Raylan goaded him, because Boyd was too smart for that. He knew Raylan would kill him in any quick duel. So Boyd played the only card he had, telling Raylan he would have to kill Boyd in cold blood if Raylan wanted him dead, Boyd betting that Raylan was too decent deep down to do that, and Boyd figured right. He goes off to prison instead of a grave, and Raylan gets to do the right thing by Art.
Back to the old-West-like draw in which Raylan is grazed: Ava uses the opportunity to escape from Raylan yet again, and she stays out of his sight for four years. When Raylan catches up with her he learns she has a boy - Boyd's boy - but even before that it's pretty clear that Raylan wasn't there to bring Ava in. He just wanted to show her he could find her. A great ending for these two characters.
And Raylan does one last thing for Ava: he goes to see Boyd in prison with a convincing story that Ava is dead. Boyd apparently believes him, and that's where this great series ends.
But does it? Is the story really over for these characters? Well, Boyd is if nothing else preternaturally clever, and I'm thinking he'll sooner or later see some kind of hole in Raylan's story and realize Raylan was lying. Meanwhile, we've seen that Raylan's not with Winona in Florida, and I'm still thinking he has some love for Ava, so - well, he can always go back out to California to be with her.
Who knows what the future will bring. As for the past, Justified can be counted as one of the best shows in our current golden age of television. I didn't review it here as often as I should have. I'll miss it.
See also Justified 6.1: Low-Flying Duck ... Justified 5.1: Finest Words Around ... Justified 4.1: Literate Boyd Quotes Asimov and Keynes
crime involving squirrels