When his friend Donald needed a kidney to save his life, Thom agreed to donate his.
About four months after the kidney donation, Donald was in a car accident during which he flew through a windshield and fractured his skull, causing brain death. Upon finding this out, Thom asked the doctors if there was any way he could get his donated kidney back. His rationale was that Donald wasn't using it for the agreed upon purpose, saving his life, so Thom should get it back. He threatened to sue the hospital if they didn't agree to give him the kidney back.
When he found out that Donald had suffered cardiac death while waiting the six hours to be cleared to donate his organs, he was very upset about losing his friend.
He was friends with Donald from seventh grade until Donald's death. They were close to the point where Thom donated a kidney when Donald needed one to save his life. When Thom found out that Donald was brain dead, he became upset that Donald wasn't holding up his end of the contract by living.