Is a Muslim who was unable to fulfill his promise for reasons beyond his control considered to have committed something forbidden and to be characterized by the traits of hypocrites, or is he excused?

Fulfilling promises and covenants is a characteristic of believers, while breaking them is a characteristic of hypocrites. If a believer breaks his promise, he is either excused or not. Excuses that negate sin include: forgetfulness, being coerced into breaking the promise, promising to commit something forbidden or neglect an obligation (in which case it is impermissible to fulfill it), and the occurrence of an unforeseen event that prevents fulfillment, such as severe illness or the death of a close relative.