Based on human inertia of thought, Truman felt that given Albert's magical talent and accomplishments, inventing some magical charms or spells shouldn't be too difficult. In reality, however, Truman had indeed never heard of Albert having any profound attainments in charmwork.
If pressed to name one, the most famous would probably be the Homorphus Charm aimed at werewolves.
Yet Truman remembered that Albert had once publicly claimed the Homorphus Charm was not a spell he had invented, though people still stubbornly insisted that it was.
Chapter 1551