Other guy has no infections (no swirly things around his head), he's killed me over twenty times in this private match and yet it's not getting passed on. What gives?
Other guy is level 9 if that changes anything.
-
It's possible he's not high enough level. I believe being infected will trigger a quest that may send you to the plaugelands. As a low level, he'd be destroyed by the level 42 enemies.