The problem with Minjee is even a meme at this point, she is basically every NTRman main heroine that is so weak to cock that turns into an idiotcockjunky in a nutshell. That being said I always thought Minjee wasnt innocent the beginning, she is just a very foolish and probably disloyal girl from the beginning, also the outbreak is probably making her more propense to commit such acts. She mentions she always fear Daeshin never comes back from scavenging, sometimes she feels useless and when she sees any other man she cant help but compare Daeshin with them, even Liam mentions she is basically a cheater. If you contrast her interactions with the police woman you can see a clear difference in character and why the police woman is number one best girl after Hyuna offcourse. Hyuna literally wants us to abandont Minjee.
Multiple paths add replayability to the game, is not weird for VNs to have mutiple paths, actually TotD is very small when it comes to paths and choices, other JPVNs have tons of paths and even crosspaths.