Ok, both characters that have the potential to kill themselves are bugged.
If UB manages to kill himself with ooze, even during a fight, it gets a "killed himself" message, and the opposition recieves no gold, EXP, or kill.
If Erebus ganks himself on his own poison blood, he gets the kill (assists are still handed out to the relevant enemies), the EXP, and the gold. I'm not sure, but he also might get EXP for ganking his teammates this way. A very useful bug if you feel like exploiting; anybody pressing a tower could easily convert their first death into another push and money to fuel their next artifact.