It seems regardless of how you register them it is always OR. I register my filter like this:
Lua Code:
local filters = {
REGISTER_FILTER_COMBAT_RESULT, ACTION_RESULT_DIED,
REGISTER_FILTER_COMBAT_RESULT, ACTION_RESULT_DIED_XP,
REGISTER_FILTER_COMBAT_RESULT, ACTION_RESULT_KILLING_BLOW,
}
EVENT_MANAGER:AddFilterForEvent(handle, EVENT_COMBAT_EVENT, unpack(filters))
and receive events for any of the 3 cases.
The lifetime is something I would be interested in too. I register them multiple times right now. No idea if that is necessary, or maybe even causes some trouble.