He was trying to commit suicide. Right before that, he had gotten into a huge fight with his girlfriend, left his home, and jumped over the fence surrounding the pond, and walked into the water with this clothes on.
Jumping into a pond to save a person life isn't the issue here. They didn't have to, there is no Florida law that says you have to render aid. Because the state can't and doesn't want to be responsible for people putting their lives at risk. Can you imagine the lawsuits? The state is trying to get them for not calling 911. You are required by law to report any and every death.