I've had exactly the opposite with my German Shepherd, we've been at a park or a music festival with Sabor on his leash and toddlers (up to about 3 yr old) have run up and thrown their arms round his neck* now I knew the dog was fine around kids as at the time we had 4 grandaughters but another dog could have reacted badly. I don't know what the kids thought he was...............giant teddy bear?...............but Sabor would have had one of his bandanas round his neck so maybe. Once the parents heart rate had come down I'd explain to them that maybe it wasn't a good idea to let their young children do this, other dogs may well react differently but my lad had been socialised very well.
* the look on the parents faces was priceless.
And if anything happens it would obviously be the dog's fault and not the parents..