it works..its a glitch it melees with the object you`re holding and the weapon at the same time so technically its a ``double melee`` but its just 1 animation MONSTER MELEE lol and i believe its off host. you just hit melee reload and fire at the same time.
I can`t say that the other guy wasn`t weak because I wasn`t there, but there actually is a double melee, ( or melee glitch w/e) that works with the ball. If you don`t believe me I could show you.