Is one who pledged not to publish rare recordings of a reciter, then published them, sinful, if the owner hoards and refuses to publish them?

Contemporary scholars have differed on the ruling of duplicating tapes, discs, and the like, holding three views: absolute prohibition, whether for commercial purposes or personal use, which is the opinion of most Fiqh academies; absolute permissibility, on the basis that prohibition constitutes concealing knowledge; and permissibility for personal use but not for commercial purposes. The preponderant view is that of absolute prohibition, and accordingly, whoever disseminates these recordings without the owner's permission is sinful.