[VEN]

Urahara:

Tutorials are good thing but in this case you obviously missed main point.
Traceline is a traceline and even such entity and origin checks will not tell us whether shot was fired or not.
Traceline is an "universal tool" which engine uses for doing many things and to filter out shot event you have to do more complicated work than that (at least with that method).

Also last player on the server (if it's connected) shouldn't be ignored in that code: skip_ent <= get_maxplayers()