What actions in this novel can not be undone and why?

Hank Mitchell, his older brother Jacob and Jacob's friend Lou are riding together in Jacob's truck when a fox runs across the road in front of them. The truck ends up in a snow bank and Jacob's dog runs after the fox. The three men go after the dog and after hiking about a half hour, find an airplane that has crashed in the woods. Goaded into going inside to check on the pilot, Hank finds the pilot dead and a duffle bag filled with money. After some discussion, they agree that Hank will hold the money for six months and at the end of that time, if no one comes searching for it, they'll divide the money and each go their separate ways, richer than they'd ever imagined. Almost immediately they encounter the local law enforcement officer, Carl Jenkins, and Hank makes the impetuous decision not to turn the money in.