Along with his co-counsel and former law partner Don Tamaki, Lee dusted off old property cases studied more closely by first year property law students than by trial attorneys. The only relevant precedents were obscure wild animal disputes, most from the 1800s and from states other than California. Despite the obvious differences in the facts, Popov v. Hayashi was reminiscent of one of the most famous of all property law cases, Pierson v. Post. The case arose from the dispute over the ownership of a fox between two hunters in New York in 1805.

"This is one of the first cases you read in law school and it really sticks out in your mind," Lee now says of Pierson v. Post. "The winner was the one who came in last."

Much like the Bonds ball trial, Pierson v. Post involved two men both claiming possession over the same valued moving object. One hunter, Post, had chased a fox for miles across uninhabited land with hounds and guns and while he was closing in on the fleeting animal, another hunter, Pierson, came along and killed it. The court ruled in favor of Pierson reasoning that because the animal did not belong to anyone, the person who seized the fox gained rights to it.

"We indicated by means of the precedent set in Pierson v. Post that you have to do more than just want the ball," Lee says. "The person who killed or mortally wounded the fox was the person who was achieved ownership."

Lee wrote in his trial brief that Pierson v. Post established "unequivocal dominion and control." Through this reasoning, he claimed only Hayashi gained complete possession of the ball.

"In this case, everybody wanted the ball and wanted it badly," says Lee. "In these things, luck plays a huge role. Patrick looked down at ball, his eyes got real big, and he put the ball in his pocket."

Lee and Tamaki followed in their brief with the 1861 case, Eads v. Brazelton, over a sunken wreck lying at the bottom of the Mississippi River. A man named Brazelton placed a buoy over the wreck, which contained lead cargo, to mark it and did not return for months at which time he found that another man, Eads, had taken the cargo. Brazelton sued claiming that the cargo was his, but lost.

"Like Brazelton in Eads v. Brazelton, Popov located the ball, but failed to secure it, or to otherwise convince the world that it was his," Lee stated in his brief.

Attorneys from both sides dug up numerous wild animal cases, including Swift v. Gifford, an 1872 whaling case cited by Popov’s attorneys. This dispute arose when a crew of one ship harpooned a whale, but before they could seize it, lost it to a second crew that came along and hauled up the whale for themselves. The court awarded the whale to the first crew. One of Popov’s three law professor expert witnesses, Paul Finkelman, of University of Tulsa, described the analogy to the Bonds ball case in his essay published before the trial, "Fugitive Baseballs and Abandoned Property: Who Owns the Home Run Ball?"

"This case was limited to the whale industry, but the analogy is useful," Finkelman wrote. "Having the ball in a glove is analogous to harpooning the whale. Thus Popov gained ownership when he caught the ball and had it in his glove."

Lee fended off the precedent set by this whale case and others by establishing the importance of "the customs and practices" of the industry in whaling and how they applied to baseball.

"We looked at number of whaling cases and the customs differed for different kinds of whales," Lee says. "For the sperm whale all you had to do was to get your harpoon into it to claim ownership. For the right whale, a more passive animal, you had to harpoon the whale with a line attached because it wasn’t a likely to get away by swimming down under. For yet another whale, you had to shoot an explosive harpoon and kill the whale until it sunk and washed up on shore. All this was important for baseball because the video showed that the ball first hit Popov’s glove, but it was only in there for six tenths of a second and not caught securely. The question became, ‘What is a catch?’ The custom and practice of the past 70 years, about what constitutes a catch in the stands, is very similar to the definition of a Major League Baseball catch. If you collide with somebody else, or hit the ground and the ball comes out of your glove or hand, it’s not a catch. If you look at what has happened in the stands for many, many years, the person who comes up with the ball is the one who gets it."