As I said before, Herbert is most likely alive with a distant relationship with Walter. But if you’ve read Lars day 9 there is a heap of information that can definitely lead to a lot more conclusions about their relationship and the possible “Incident”. I definitely believe that Herbert was involved in said incident because of the information in Lars day 9. I believe that the “Incident” could’ve been a mistake that Walter made because of the constant guilt he feels in his flashbacks (although he might just feel guilty for no reason).
I’m just mostly questioning why they are distant and if it relates to the “Incident”.
Other than that I believe you’re right.