After posting the above, I went and played my human ship for a while. In the current sector, I'm mostly working for the human faction.
The Talon have popped up 3 times so far. Each time, they destroy a human colony and take over the planet. Each time they do so, I go and wipe out the Talon colony. Yet, the Shadow always get credit for destroying Talon.
The message text goes like this..
Shadow destroys Talon: credits seized 156, technology gained: 1
The colony on Mewtus (Talon) in Micorn has been destroyed by Vanguard (Drox Operatives).
Also, now that I think about it, the last two sectors where humans were a faction, the talon popped up and it was to destroy a human colony. I can't say for 100% certainty, but I don't believe I've ever seen them wipe out some other race's colony in order to take a planet.