An enemy pokemon that fainted still attacked me before officially dying and switching to the next one

[Former user]

In my gym battle vs. Anastasia I killed the klefki but then it still used foul play on me before fainting and Anastasia switching Metagross in. Sorry if this is a duplicate, I didn't see the same issue posted yet.

[Devin Ullerick]

Also happened to me in the first trainer battle on route 11 against the Dedenne, still used discharge after dying.