One 16-point loss does not a playoff series make.
Six times the Sixers have lost playoff game by 16 or more points and come back to capture the series (below).
That includes the grand-daddy of them all, the 40-point loss to the Celtics in Game 1 of the 1982 Eastern Conference Final. They went on to win the next three games, then dropped Games 5 and 6 before winning Game 7.
(By the way, the Sixers have lost 21 postseason series when they suffered a loss of at least 16 points.)