That's not true. The actual number is 15. What you are looking at is what every batter that made an an out at any time and how many were on base when that out was made. LOB is how many were on base when the inning ended. Not how many were on base when the 1st, 2nd and and 3rd out were made.
The Yahoo scoreboard does the same for each hitter, but they also show the team LOB (how many they left when the inning ended).