Lots of potential problems with retaining that filter bowl. Key elements appear in the report but not all of the potential problems are highlighted. Using a stud certainly has the advantage of bringing the regularly-dismantled threaded joint out to where the maintainer can observe it properly and makes nut replacement simple. However, at the same time, it provides for two threaded joints that can cause problems instead of just one. Then there is the length of the stud which is not great enough to allow significant stretch under preload and therefore is highly prone to loosening. (Locking wires and such like don't prevent loosening if aspects of the threaded fastener design are poor.)