Killing the ancient dragon (SpellForce 3)

Caught a bug with killing an ancient dragon or something not understood.
as I understand it there are 3 options of interaction with a dragon. 1 and 2 are very similar.
1) we accept the help of the dragon hunters, they give us a quest to kill Wyverns, but I warn you that heart can take it by yourself, and will give us only the scales for armor.
2) we refuse the help and go shred the lizard themselves, but these dragon hunters still break into our fight and after the victory say take heart, but we can refuse them and say that we pick up all.
3) do not kill the dragon, and to fulfill his Commission and receive from him a reward or a weapon and shield, or quite fit the ring on the mage.
So, I was wondering podnijeti and pick up all myself, so I refused and said not give heart after I killed them all, I got nothing. no loot, this is a bug or how you can skin the carcass of our dragon? and if someone figured out where you can apply his heart and other parts of the body, maybe somewhere there is another Crafter dragon armor?