The term sine-qua-non means 'without which there is nothing.' The meaning behind this is that something has to exist for something else to be true. It is usually referenced in criminal law and contract law. Criminally, it means that a crime could not have occurred were it not for the fact that something else occurred. For instance, the defendant would not have killed a person by hitting them wth their car if the defendant had not been drunk and driving too fast. In contract law it would mean that a loan could not exist were it not for the fact that a borrower applied for a line of credit.
Guilt can be inferred through sine-qua non by the fact that responsibility exists within a person or party that begin down a specific route and were it not for their actions the following actions would not have occurred. In this way, liability and blame are placed.