Unlocking that fucking jacket takes such a specific setup that it feels like you're trying to trigger an obscure easter egg that requires multiple steps and setup, which this does require, because getting it naturally is so unlikely I'd bet most people missed this their first time around, I certainly did.
So, in chapter 2, some people say you need to complete a specific mission for the dialogue to trigger, some say you can do it as soon as chapter 2 begins which is likely true. I managed to do it 2 missions before chapter 2 ends, the last mission involves looking for a new place and thus the camp is dismantled and you can't get it anymore, people's standard routines are cancelled.
The setup is: Pearson the camp cook needs to ask Arthur for a rabbit to make stew, but for that to happen you seem to require to have your health core in the red, and Pearson will only say the line if he's working at his table at approximately 10 AM, if anyone else is there you need to reload a save you had made 9:30 AM, in preparation for this. If you have your health in the red and if you're lucky to draw the routine where nobody else is in the wrong place and he's working at the precise time, you need to wait around until he starts whistling, if he's drinking beer, he's behind the table working and whistling, that's the sign it should trigger, but if you take too long that part of his routine might end so you can't miss this window (ask me how I know). I think I reloaded at least 5 times until the stars aligned and he asked for the rabbit. I couldn't believe it had worked, I got this setup from reading somebody's comment on a youtube video guide talking about the jacket. There are several different guides on how to unlock this jacket on youtube and people sharing their experiences of what worked in the comments of all of them.
This jacket is the most missable piece of content in the entire game I think. People say it should work in later chapters but it's glitched, I've even heard people say this isn't on the official game guides. Just a really odd thing that I dedicated a little bit of time to try and get and got it, so now I'm able to tell this story lol.