Two companies entered into a contract for the supply of medicines and other health products. After receiving €337,596.00, the supplier stopped delivering the products and retained this amount, claiming it would cover losses allegedly caused by the other contracting party’s unlawful conduct, as one of its managers was diverting clients, which, up to that point, had resulted in a verified loss of €855,000.00. In reviewing the case, the Supreme Court of Justice of Portugal characterized the supplier’s conduct as precautionary self-help (direct action) in the form of seizure but considered it unlawful due to disproportionality, since it did not meet the requirements outlined in Article 336 of the Portuguese Civil Code: (a) the existence of a legitimate right; (b) the impossibility of resorting to judicial or administrative enforcement measures in due time; (c) the action being necessary to prevent the practical frustration of the right; (d) the absence of excess in preventing the loss; and (e) the direct action not resulting in the sacrifice of interests that are more important than those the agent seeks to protect.