My neighbor, across the street, has a GSD. And he was warning me never to touch my puppy's ears because I could damage them. I've been around GSDs most of my life, but had never heard that one before, so I asked my Vet about it. She said there's nothing at all to worry about! A puppy's ears can be damaged by rough play with other dogs or puppies, but even that is pretty rare, normal petting or massaging of the ears is fine!
It's not the size of the dog in the fight, it's the size of the fight in the dog. Mark Twain