That is a really interesting video for several reasons.
1) This is clearly no simple robbery. I don't know what those guys are after, but DANG, they're determined. So much for the idea that bad guys are cowards looking for easy prey. They know the guy has a gun, and he shoots one right at the start, seriously wounding him. Then shoots at a second one, apparently missing. And then shoots the third guy, obviously wounding him as well. This hardly phases the attackers. They're still pursuing (except for the one gut-shot fellow who decides to sit it out). Again, the motive here is unclear but VERY serious because death doesn't seem to be a concern for these guys.
There's a weird overall feel to this, like it's more of a confrontation than an intentional murder scenario. Not sure, again, if that's a cultural thing or what, but the attacking guys could easily have overpowered him if they'd bum rushed him in the first second or so. Instead there's a sort of milling around, "oh, no, after YOU," appearance to the thing. As though a relatively inexperienced group of local toughs are coming by to beat this man up, maybe teach a lesson (maybe he's not paying his extortion money, maybe he slept with someone he shouldn't have, who knows?), and don't really expect him to be armed. Then finding he's armed and willing to shoot, they make a sort of re-group effort and decide to tough it out. There certainly seems to be no plan for getting shot, and sitting it out bleeding into your own guts, or hobbling around clutching your leg doesn't seem like a good exit strategy.
2) What is up with the gun/ammo? I think I saw three shots fired, two hits, one miss. That revolver would hold at least five, and probably six. Perhaps there are a few more shots fired after the defender steps back out of the camera's view. That could explain the sudden rush the remaining attackers make toward his position. (If he fired and missed three more times.)
3) The two shots that hit were effective enough, though poorly placed. He does take those two guys out of the fight. Again, though, the two men in white really don't seem to care much. Whatever their beef with him is, the wounding and possible death of their two comrades doesn't deter them.
4) When you see four men approaching you with sticks and machetes, don't go out to greet them, and don't go hand-to-hand with one while the others close in. That would seem to not need to be said, but ...well, that's what this guy does. Perhaps there's a strong "don't shoot first" preference in that culture, I don't know. As the defensive instructor's voice-over says, you've got to use the great distance advantage of the gun. Verbal warnings if there's time, then fire if it's obvious they're still closing with lethal intent.
5) Yes, capacity matters. Whatever happened with the gun and ammo (3 shots? More? We don't know...) the defender had no way to engage his threats with the sort of response we in the west tend to preach, of multiple hits to center-of-mass. There was certainly plenty of time to have put three or four rounds into each attacker within the first five or six seconds but he didn't have the ammo to do so. While it's hard to get into these attackers' heads, even though seeing two of their pals shot didn't seem to phase them, advancing through a small volley of shots would have been a lot more intimidating. And, of course, more physically effective if they weren't psychologically deterred.
6) Again, the culture question. This defender does not seem to be very familiar with his weapon, nor have much of a clue how to use it to mount a serious defense. I have to assume that seeing events unfold something like this is what prompted guys like Col. Cooper, Reed, Chapman, Weaver etc. to start to try to come up with a practical method for effective pistol combat.
