FromGermany, of course, you are correct. BG is carrying a gun or maybe two. [One for each hand.] Perhaps instead of a fishing vest, we should consider a tactical vest. BG was not out fishing that fateful day.
A tactical vest holds items outside of the vest, as previously mentioned. Items such as extra ammo is carried in these vests. There are small pouches to hold one's package of cigarettes, if one is so inclined to be a smoker. These vests can even hold grenades. Metal clips hold knife sheaths. Does a tactical vest make more sense for BGs purpose than a fishing vest? (Thinking of you, gliving.)
I believe that BG may be a skilled hunter, fisherman and, perhaps, knows how to catch big fish; trap animals; track, shoot and skin deer; shoot turkeys with arrows, and so forth. In my opinion, this person wears his tactical vest as part of a normal daily routine of skirting a thin line to becoming obsessive. Also, his vest could be armour-plated, as in bulletproof. Yes, a definitely plated vest.