Responses
The mother refused to leave his side so when the dragon attacked she didn't leave him.
As for them being heros, they had already exhausted all their strength against the zombie hoard and the dragon was too much after all that.
Even merlin was only able to keep himself safe and that's saying a lot.
So the father was badly wounded, I understand. But why did the mother die too? ? And generally, why were three heroes so powerless against the monsters???