<?php

$Turma = array(

array("nome" => "Diogo", "score" => "100", "time" => "6" ),
array("nome" => "Joao","score" => "500", "time" => "3" ),
array("nome" => "Miguel", "score" => "125", "time" => "8" ),
array("nome" => "Daniela", "score" => "105", "time" => "7" ),
array("nome" => "Joana", "score" => "100", "time" => "6" ),
array("nome" => "Diogo", "score" => "275", "time" => "4" ),
array("nome" => "Francisco", "score" => "300", "time" => "9" ),
array("nome" => "Ines", "score" => "650", "time" => "2" ),
array("nome" => "Dionisio", "score" => "101", "time" => "10" ),
array("nome" => "Ricardo", "score" => "200", "time" => "8" ),
array("nome" => "Fabio", "score" => "201", "time" => "11" ),
array("nome" => "Tiago","score" => "50", "time" => "13" ),
array("nome" => "Carolina", "score" => "150", "time" => "5" ), 
array("nome" => "Rui", "score" => "130", "time" => "3" ),
array("nome" => "Luisa", "score" => "1000", "time" => "1" ),

);


usort($Turma, function ($a, $b) {

	$resultado = $b['score'] <=> $a['score'];

	return $resultado === 0 ? $b['time'] <=> $b['time'] : $resultado;
});

print_r($Turma);