They weren't using arrows of detonation, but wands of fireballs.
Okay the scenerio was what I got out of the Dragon Mountain adventure. A group of kobolds raid a village the PCs were in. They used one shot wand of fireballs (5d6) as the initial surprise round attack. A lot of villagers died but the party was on average still had half their hit points left. After the wands were used they kobolds switched to crossbows to pick off anyone still alive. At the end of the combat 2 PCs were down but not dead while the rest were in sad shape. They could have easily ran away since the goal of the kobolds were to destroy the village and if people ran away that meant less work for them.
In any case one kobold was captured by the party and that kobold was named Killit Kwik, which I thought it would be a good clue for the party but it wasn't. The monk of the group stood up for Killit and even gave its unused wand of fireballs back to him. They told Killit that if he leads the party to where the kobold came from they would let it live. The kobold readily agreed.
Well, that lil' Kobold led the party to the lair alright. The kobolds were servitor of a great wyrm half fiend red dragon and led them right to an ambush where 1 party member was indeed killed and the monk had a fireball hemmorroid. 3 other party members were down and 2 of the survivors picked up their friends and ran away.