Here's a reasonable explanation that I found.
"Because it's not a very clean process. 14 numbered balls are put in a hopper and a 4 number combo is drawn. That 4 number combo is compared to a list of 1,000 potential combinations assigned to the 14 teams. So it's not as if the #1 ball comes up and you know that's assigned to Sacramento. Instead, for example, the numbers 2-4-7-13 are drawn and compared against the matrix and the team with that combo wins. Then it's possible you could have multiple drawings hit for the same team, and would then get thrown out. Not as TV friendly as your local state lotto Pick 4 drawings. I guess they have "Independent Auditors" oversee the process... but at the very least I'd like to see them invite some media to watch."