I have verified this problem on 2 different IRCx networks.
It seems that mIRC is not recognizing the raw non-numeric event for KILL on these servers. You can see mIRC receive it by looking in a debug window but it won't parse in scripts.
I tested the 3 following techniques:
raw *:*:{}
raw KILL:*:{}
raw KILL*:*:{}
The on DISCONNECT event does still trigger but, it does not return suffcient information to identify a KILL.
