Fulham had a poor first 15 minutes. That in and of itself wouldn't be the end of the world. Even though they gave up a goal, it wouldn't be an impossible task to recover from. They've had bad stretches in games before. Most teams will have a stretch of 10 to 15 minutes where they are thoroughly outplayed. However, once Marcus Bettinelli got sent off and conceded a penalty, the game was effectively over.
People will complain about the defense, but I'm not sure what lessons you can learn from this game. Sure they let in three after dropping down to 10 men, but what could your really expect? Especially with Gabor Kirlay in at keeper. Fulham need to improve the defense, getting Hoogland back will help; but they may need to enter the transfer market to improve at fullback.
This is a bad result to be sure, but it's probably best to forget it and move on to the next one. Winning on the road at Leeds isn't an impossible task, and beating Sheffield Wednesday at home is something the boys should be able to do. When those two and it won't be hard to forget this result at all.