"Ditto glitch during gym battle, Muk transformed into Dragonite"

#PokemonGO: Today I was knocking down a level 10 gym in my town and this happened when last 2 Dragonites were remaining. I chose some trash pokemons for this battle. I chose1. Omastar2. Ditto3. Muk4. trash5. trash6. trash(I don't remember last 3 pokemon)When my Omastar was about to die, I selected Muk and when I reached again on battle screen Omastar was died. Immediately Ditto appeared on the screen and transformation animation started. In between this animation Ditto was replaced by Muk and then Muk was looking like Dragonite although its attacks or other stats did not changed.When Muk fainted Ditto appeared disguised as Dragonite. Screenshots here via /r/TheSilphRoad http://ift.tt/2fCEIHH