Enemies don’t have to land the killing blow or even be responsible for it on a droid to trigger GG’s turn. Palp’s special, magnaguard’s bonus turn then dying (technically his unique that defeats him), and GG’s unique dropping B1 all trigger GG’s turn, among other abilities. With B1 though, if GG’s unique takes him out he doesn’t reset his cooldowns like the text suggests. Idk what the status of some of these weird “possible” bugs are, but if they’re WAI, they should adjust the text to match.