Is a man shaking hands with a non-mahram woman considered a sin if it happens quickly and without thought, especially if the man believes he is bewitched and that the magic might have affected his behavior?

Deliberately shaking hands with foreign women is an abomination and must be avoided. If you did not intentionally touch a foreign woman and quickly withdrew your hand, then there is no sin upon you, God willing, as Allah Almighty says: "Our Lord, do not impose blame upon us if we have forgotten or erred," and "And there is no blame upon you for that in which you have erred, but [there is blame for] what your hearts intended." A Muslim should seek treatment and remedy through lawful Ruqyah and permissible things if they are ill, for the strong believer is more beloved to Allah, and the Prophet, peace and blessings be upon him, commanded seeking treatment.