Thanks for checking out the demo and nice catch with the calls from Miller turning back on after the cutscene, that's a new one! We're working on the guns respawning, will be pushing an update to the demo soon that should address that.
Well, I've not checked if it turns back on. I never took the path when playing through it, so when I explored down it, miller chimed in despite... well, you know, the mission being over and all. So yeah, another flag to look into. As for the weapons respawning, best of luck getting it fixed. ...Sure wouldn't want that to happen in later levels where you keep your inventory. Yep, sure wouldn't want that....