Board Thread:Character Discussion/@comment-26814591-20150724030749/@comment-25176701-20150724134143

To OP: Please go to the Finn page and scroll down to find the link where Jason confirms he had PTSD after the events from S1 (an anon user was kind enough to post it for people who couldn't figure it out on their own/people who kept denying it). Believe me, it will save everyone's time.

As for the Grounders, how the fuck were they innocent? They were warriors, just like the Delinquents had become. The Grounders are the murderers and the Sky People are the victims. Nobody on The 100 is fully innocent. The Grounders weren't either. They are savages and even they think so. This is supported by Clarke and Lexa's conversation in 2x08:

Clarke: "Show them you're not a savage." (rest cut out for the sake of time)

Lexa: "We are what we are."

As for why they didn't want to give Finn up, it's because the Grounders couldn't be bothered to show him any mercy. They wanted to brutally torture him to death. Why would you send a good, peace-loving person who developed PTSD due to somebody else's sick violence to be brutally tortured? If Finn was somebody like Dr. Tsing, then yes, he should have been given up. But Finn was no Dr. Tsing.