That's what logging important IM conversations is for 
As for where to start, it looks like AbilityStealResources and its corresponding BuffStealResourcesTarget seems to be what I was thinking of:
instantAction
buffInstantActionType "StealResources"
instantActionTriggerType "OnBuffFinish"
resourceToSteal "Credits"
resourceAmount
Level:0 100.000000
Level:1 0.000000
Level:2 0.000000
Which looks like it gives a flat 100 credits, and looks like it can be used for other resource types. Doesn't seem to be a way to trigger it on target's death, though.. so I don't know what exactly StCobalt was talking about 