Negligence occurs when a party does not do what is required of him in a given situation. It is being careless with one's responsibility.
Contributory negligence is when one does not show sufficient care for himself or is acts in such a way that contributes to an accident.
If a defendant is able to prove contributory negligence in the case of an accident the plaintiff will not be able to recover any damages.
For example if one enters a busy road when a green light for cars was on and there is an accident. He put himself in harm's way and will not be able to claim damages because he has contributory negligence
His contract is technically legal by certain states considering the acceptable age group to get a job is 14, according to state laws. There are chances Ahmed could have ran into a scam, though, as this is a common issue today. Such as the chance it was just a false ad, or maybe a money scam.