What it shows is that 159-0 will likely never be duplicated. One reason is you likely won't ever see a guy wrestle 159 NCAA matches again. The other is it is almost impossible to not have an off day, get caught by something, or someone just being better that day.
Most would agree that Spencer Lee has been one of if not the most dominant wrestler in recent years and he has 5 losses.
It is truly amazing to go your entire career without losing. It is hard enough to do it for a season.