e indorsement of a document of title issued by a bailee does not make the indorser liable for any default by the bailee or by previous indorsers.

§ 7506. Delivery Without Indorsement: Right to Compel
Indorsement.
The transferee of a negotiable document of title has a specifically enforceable right to have his transferor supply any necessary indorsement but the transfer becomes a negotiation only as of the time the indorsement is supplied.