I think somewhere north of 90% of the "Clinton Death List" stuff is nonsense but there are definitely some dodgy things in there too.
The oddest thing in this case seems to be the missing gun. I haven't seen (in an admittedly short search) any official hypothesis for this. Are they assuming someone walked by and thought, "#### it, dead dude but yay...free gun" and ####ed off with it? If not then they should be assuming another person was involved surely?