That makes no sense, because both instances of power/property proc off different things. One is off "making an attack" and one is off "hitting with an attack."
But both are part of using a power, which is what matters. It specifically says that you can't use both when using the same power.
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Twostuck, Homestuck RPG: http://www.gamefaqs.com/boards/8-gamefaqs-contests/62168402