Did you know, that ... (Part 70)

.. that if a vampire you control hits the opposing vampire just for one damage (e.g. by handstrike) and your vampire was hit by Theft of Vitae, the vampire you control can still play Disarm (which requires you inflict more damage than the opposing vampire).

This is because strikes stealing blood (like Theft of Vitae) are not considered a damage dealing strike, and therefore I though your vampire lost more blood than the opposing vampire, your vampire still inflicted more damage.

Props to CryWolf for the hint.