You don't really need to go to the sawmill (at least I didn't), when you hear Rose and the Girl talking about the beast and Bernard, before you go, the MC will hear an howl coming from the sawmill and then you'll have to choose who are you going to rescue.
this, it's only a choice between Bernard or Logan if you didn't encourage Logan to go the camp earlier. Location doesn't matter.
decided to test it as i was trying to find some new dialog out of curiosity about how certain characters react to things in one-time events and discovered, I was right. I went to the shopkeeper's place and then picked Logan and was able to do the entire event all over again, Location don't matter what you choose does.