x1 watches the event x2 unfold before their very eyes/live/red-handed/in flagrante (delicto), using senses/means x3.
No implication of the action being considered improper or discouraged. The event must be an action (lo nu zukte), not just an occurrence. "Before one's very eyes" is an idiomatic expression and does not require sight to have been involved, nor x1 to even have eyes.