I just looked at McFadden's stats in the game log, and it's pretty interesting. Although Oakland got blown out, most of McFadden's success was not in garbage time. Here is a breakdown of his stats:
Full game: 18 carries for 95 yards, 6 receptions for 55 yards
1st Q: 7 carries for 32 yards, 1 reception for 3 yards
2nd Q: 4 carries for 26 yards, 3 receptions for 42 yards
1st half: 11 carries for 58 yards, 4 reception for 45 yards
2nd half: 7 carries for 37 yards, 2 receptions for 10 yards
McFadden's longest run was 13 yards, and his longest reception was 16 yards. So there were no giant gains that inflated the numbers.
Looking at the game log, it really seems that Campbell and the offensive line was struggling. McFadden had a really good game despite all that. My cojones feel less raisin-like.