This is nonsense, and typical layman logic when it comes to matters involving abandoned property and theft when on another premises. It is not even remotely inline with reality. In almost any jurisdiction in the US, one has legal recourse when someone takes their money or property. Whether it's in the other's control or not, it's still just as equally defined as theft.
If property is the subject of a reasonable dispute-- e.g. whether a contractual term applies-- whomever is holding the property has the upper hand. Especially if the amount of property/money is small compared to the probable cost of litigation and especially so if one is unlikely to recover legal fees.
It's not completely nonsense, but maybe it kind of dances around the point. 99% of the time people don't have any legal access whatsoever because it's much too costly. Practically, people only have legal protection in catastrophic scenarios, where they have no choice but to pay exorbitant fees. So good luck getting your property back in 9/10 cases.
