Ok, Level 7 PC vs. Adult Dragon (CR 13 – CR 17) with a NPC in the middle. Oath of the Ancients (PHB). Be a shining light of goodness and hope. Protect life. Be happy. Let your light Shine.
The OP DM gave the player a no win situation. Did you talk with your player about the code of conduct and how you view it? Does his gawd demand suicide charges? Is this a set up for a new adventure? A setup for a side quest for the pc? Did you communicate well with the player?
I would have the gawd talk to the pc in the dream state. (And DM and player need a conference). At best I would pull his second level spell slots for a week. As the paladin, I am finding the nearest sending stone, message bird, message, candygram, telegram, tell a woman, smoke signals, or internet café and calling for help. HEY YOU PALADINS ANCIENT OATH OF GAWD XYZ STOP. DRAGON DONE ATE MY NPC STOP. SEND HELP STOP. SENT COD STOP.
If I was home brewing, I would have a generic set of a code of conduct for each oath. Then I and the player would adjust it a little for his gawd, and his view point. I would never set up a NO WIN situation unless two conditions exist. One. I am pulling a fast one pay no attention to the rabbit ears sitting out the hat. Two I had made very plain the pass couple of actions by the pcs and paladin have put the paladin on the highway to hell and he has forgotten the toll booth change.
I do agree with
@Celebrim the paladin violated his oath. BUT I know we are missing what exactly happen at the table. I don’t believe that BOOM Dragon appear. Dragon “gives us our snackage!” Paladin, “Here you go!” I think the dragon appeared. Dragon “Gives us our snackage!” And more conversation took place with the result being here you go.
Snark. If the dragon ate the paladin would be considered a light meal? Light in calories? A religious diet?
Snark. TWEEET. Two flags on the play. 1 DM not communicating possible win condition. Penalty one slice of pizza and one mountain dew. 2. Player giving up NPC with no fight. Penalty One slice of pizza and one mountain dew. These being offsetting penalties we go to the box for an IC solution and OCC solution. OOC (took me a minute to figure out what OOC meant). All the gamers have discussion before next game about DM version of paladin CoC. IC depending if “Story” matters to group, paladin is denied some paladin abilities for x game days. Suggestion all players decide to hunt dragon down for a good flossing. Or dragon is handled off scene by bigger badder paladins.