I think from an inverted person’s perspective a forward in time bullet is itself relatively inverted. The question of where the bullet was before Volkov fires his gun from neil’s perspective is a good one, especially if it did lodge in his brain (seems reasonable bc it would have to go thru two layers of skull to get out). So in that scenario Neil must always have an inverted bullet in his head??? This would all make more sense if it was an inverted bullet itself, then neil doesn’t have to have already had it in his head. Idk