Short answer. Yes. Someone who takes over another's affairs without authority — an officious manager — must act with the diligence of a good father of a family, and answers for the damage caused by his fault or negligence. The court may raise or lower that indemnity according to the circumstances of the case.
What the law says
The officious manager shall perform his duties with all the diligence of a good father of a family, and pay the damages which through his fault or negligence may be suffered by the owner of the property or business under management.
Civil Code, Article 2145 — Gestor's Diligence. Read the full provision →
What the law says
The courts may, however, increase or moderate the indemnity according to the circumstances of each case.
Civil Code, Article 2145 — Gestor's Diligence. Read the full provision →
Stepping in creates real duties
When you voluntarily take charge of another person's property or business without their request — what the law calls negotiorum gestio, and the person doing it an officious manager — you do not act as a bystander doing a favour. The moment you assume the management, the law attaches obligations to it. Good intentions in stepping in do not lower the standard by which what you then do is judged. Article 2145 sets that standard and makes clear that mismanagement has a price, however well-meant the intervention that led to it.
The standard is a good father of a family
The measure is not perfection but ordinary prudence: the manager shall perform his duties with all the diligence of a good father of a family. That is the same care a reasonably careful person takes with his own affairs — attentive, but not extraordinary. You are not held to the skill of a professional you never claimed to be, yet you cannot treat someone else's property more carelessly than a sensible owner would treat his own. The test asks what a prudent person in your position would have done, and compares your conduct against it.
Liability for fault or negligence
Falling short of that care carries a concrete consequence. The manager must pay the damages which through his fault or negligence may be suffered by the owner of the property or business under management. The liability is for the loss your carelessness actually caused — not for every misfortune that befalls the property, but for the harm traceable to your failure to act with due diligence. An owner who returns to find the business damaged by the manager's neglect can recover that damage from him, the intervention having been unsolicited notwithstanding.
The court can temper the amount
The law does not treat the officious manager exactly like a paid agent, and Article 2145 gives the court room to reflect that: the courts may, however, increase or moderate the indemnity according to the circumstances of each case. A person who intervened in a genuine emergency, or to spare the owner a loss he could not prevent, may see the indemnity reduced, while one who meddled recklessly may see it raised. The discretion recognises that unsolicited management can be helpful or harmful, and lets the outcome turn on which it was here.