This can generally happen with any melee-based ability, done by any character.
Here's a pretty old thread of mine - still relevant. Sometimes a simple trooper's melee can kill your hero unit - while said trooper is already dead, but his melee is "lingering in the air", repeatedly hitting and damaging you.
Thanks for the Melee case @felker_s , I'll test it as well. I did test all 3 characters (Maul, Luke, Phasma) on splitscreen arcade, and it's fairly easy to reproduce this BUG there. I'll release a video about it after I test the melee.
