Elite Monsters and Elite Bosses

I would like to add if you log off before the elite boss summons, the elite boss will not even be there (unless someone is stalking me and has hyper teleport). I tried this 2x because I have only 1 computer. The "character" I used to summon with is too weak so I tried switching fast to my stronger one and it was gone.. I would like to mention I logged off immediately after I saw the "warning" message. I am thinking I logged off too quickly, but who knows.. You also need to make sure no one else in the same map as you if you would like to disprove me wrong on my theory.