I'm an older, non-practicing Blue Belt, and I don't have any answers.
I've tapped and been tapped with choke holds. My instructor tells a story about a student of his in a real altercation who let his opponent up in after he tapped, and who then stabbed him; if it's real and he taps, then he's still functioning.
I've also rolled with a guy who thinks it's unmanly to tap; have to be really careful with that idiot, and I hope he gets over his hangups before he gets hurt.
But as to not having other tools, I'm not sure that's true. I don't know if South Korean police have handcuffs or not, but I see plenty of pics of them using a wrist lock come-along, oppo's forearm tucked neatly under their armpit. Kimuras are pretty effective at immobilizing. Handcuffs are even better and I don't think you need a choke hold when oppo has his hand cuffed behind him; if you're afraid he'll run, then zip tie his ankles.
As I said, I'm older, grey-haired, and overweight, and am unlikely to be provoked. If I do have to use these holds, it's unlikely to be a Kimura or a wrist lock or an arm bar; how would I let him go and get clear if I have no backup? Cops have backup.