The way I see it: maybe you, like me, expected Smith to "pick up" Talas while on the return trip. However, he left her long enough ago that she would be married by now anyway. So what happens? He's not going to just take her away and he's not going to kill the husband, either. That's not in his character. So advancing the plot in that direction is probably a bad idea. And anyway her stepfather is still there and he still wouldn't approve even if she was still single. So if Smith and Talas are to get together, it has to be away from her home... thus chapter 69.
I agree the twist might feel a bit forced, but I think it was the best way to give us a happy reunion. Of course we could argue that it's Mori's fault if she wrote herself into a corner plot-wise, but what the heck, I wanted a happy end too much to care... if it is indeed the end.