CLEVELAND—Game 4 of the NBA Finals was insane, inexplicable and maybe even inconsequential. It was also just plain weird.

The Cleveland Cavaliers won, too. They became the first team to beat the Golden State Warriors in nearly two months and saved their season with a 137-116 win on Friday night that spoiled Golden State’s shot at a perfect 16-0 postseason record and sent the series back to Oakland for Game 5 on Monday night.

But...