Maybe his year of slavery in troll games and soulnames. Or his brief moment of being a slafe when he's captured by Picknose in the oq.
Anyway, I think it's great that the elves responded in that way towards the trolls. Mainly because of Cutter, no-one held grudge against them for being the reason of the High-Ones crash (except maybe for some Go-Backs) Because as wordgazer says, they understood the impact slavery and respression had on what happened.
I think it's normal that the trolls rebelled at a point.
But, as I said, I had expected a few Go-Backs to be furious towards the trolls. I know it's not that reasonable, but they had lost many of their friends/Lovers/tribemates in the war they just had fought and it would be normal if they couldn't see the trolls as anything other than enemies at that point.
On the other side, they had won their war with help of trolls. The Go-Backs rather enjoyed the fight, and their friends died an 'honorable' dead.