sweet- I dont think the girls fam has any rite to be upset. He did exactly what he was told to do according to da’as torah. If they dont want to go ahead with the shidduch they dont have to but they certainly have no right to talk about it with everyone. Also, once your at a point where your ready to tell it means there is some “sort” of relationship beginning to form (I am speaking for those who date) and if that’s the case the other party will be likely to consider you even though there’s this “issue” becuase they can overlook it when comparing it to your middos,personality etc.
happens to be that I have a relative who went out with a boy with D. After the third date the shadchan called her mother to tell that the boy’s side wants to tell them that he has D..etc. In the end they didnt go ahead with the shidduch but I wonder if the boy would have told her directly what would have happened…obviously this was what was bashert but just a thought….sometimes its good to hear it from the source..
sorry for the long post!