Who bears the cost of a device that has been damaged, when there are two distinct errors involving intent and causation?

The experts must be consulted to determine the cause of the device's malfunction and whether the initial error is related to it or not. The employee is a private contractor, and a private contractor is not liable for damage to work or machinery under his hand unless it is due to negligence or transgression, because his hand is one of trust. The reference for determining the cause of the malfunction is the experts and what the labor laws and regulations stipulate.