Short answer. Yes. Under Article 2147, an officious manager who fails to return the property or business after the owner's demand becomes liable for any fortuitous event that follows. Once the owner has demanded it back, holding on to the property shifts the risk of an accidental loss onto you.
What the law says
If he fails to return the property or business after demand by the owner
Civil Code, Article 2147 — Gestor's Liability for Fortuitous Events. Read the full provision →
The demand is the turning point
While you manage another's property faithfully, an accidental loss is generally not laid at your door. Article 2147 changes that from the moment the owner asks for the property back, listing among the grounds of liability the case where he fails to return the property or business after demand by the owner. The owner's demand marks the end of any justification for your continued control. Keep the property past that point and you are no longer a manager the law is protecting; you are holding onto something you were told to give up, and the risk changes hands with it.
Before demand and after demand
The distinction the article draws is between two periods. Before the owner demands the property, a fortuitous event that destroys it ordinarily excuses you, because you were managing it as you were entitled to. After the demand, the same accident produces a different result: you answer for the loss. The property should by then have been back in the owner's hands, and it is only your failure to return it that left it exposed to the event at all. The law therefore treats the loss as flowing from your refusal to give it up rather than from the accident.
What counts as a failure to return
Two elements bring this ground into play: a demand by the owner, and a failure to return the property in answer to it. The demand is the owner asking for his property or business back; the failure is your not restoring it when you reasonably could. Not every delay is a failure — an inability to return through no fault of yours is different from simply holding on — but once a clear demand has been made and honouring it was within your power, continued possession is at your risk. Silence, evasion, or clinging to the property after being told to return it all fall on the wrong side of the line.
The safe course once demand is made
The practical lesson is that a demand from the owner is not something to negotiate around while you keep the property. The way to stay outside this ground is to return the property or business promptly once it is asked for, and, where an immediate handover is genuinely impossible, to document why and to make the property available as soon as you can. A manager who returns what he was told to return carries none of the fortuitous risk; the one who holds on carries all of it, and an accident that follows becomes his to pay for.