They were so far behind because they won the fast forward and Took a break from racing instead of going directly to the Finish Line.
Maybe because it was the first season, that they just mis-judged the time to complete the leg, or just stupidity, they went to a hotel and ordered Lemon-aid. They rested then went to the finish line just after Mom and Emily had crossed the Finish Line. If Mom and Nancy had not given up and found there car, insted of taking the cab, Bill and Joe would have been Eliminated.