Take this (very common) scenario.

Two heroes fight. Lowbie stands next to them.

One hero dies. Lowbie loots because the victorious hero is almost certainly lagged by something that they used to prevent the defeated hero from escaping.

Voila. You have uber gear on a lowbie char.

Myself, I remember one time when I informed on an evil hero who I'd seen fighting a good aligned hero when said evil hero came into the area where I was ranking to recover. I was about level 5. The good aligned hero came, using my information, and killed the evil hero. He then took the couple of items he wanted, and butchered the corpse in order that I could have my pick of the rest of it, in return for my help.