So, i know you have likely answered this before, but recently in our last game there was an issue where I (the player) knocked a flying enemy prone using the Gunslinger Archetype Pistolero ability Twin Shot Knockdown. Now, to me, knocking a flying creature prone means i make it fall to the ground. The DM at the time was uncertain (and since he likes to try and kill me) ruled that it gets a fly check to negate the prone condition. Now, to me, thats like saying a standing enemy can use tumble to negate the prone condition as well, but, seeing as how i have never really seen any rules for this sort of happening, what would you say the ruling would be?