We were with our last pokemon the tapeworm excadrill and I dragonite attacked it and killed it first but then with the same sand dies my pokemon, he says you won points in pvp? And I respond I did not lose what he tells me I won pts and when the battle ended I said you won

the one who get killed 1st will lose, for an example talonflame with brave bird kill opponent and die due to recoil damage but it still consider as you win the game