1,746. In a Public or Third-Party Domain
Hilchos Geirushin 5:13
Let’s say that a man throws his wife a get in a public domain or in a domain that doesn’t belong to either of them. If the get is close to him, divorce is not effected; if part of the get is close to him and part is close to her, divorce is doubtfully effected until the get is definitely close to her. If the get is close enough to the woman that she can bend down and pick it up, the divorce is invalid (i.e., rabbinically); she is only free to remarry when the get reaches her hand.
Hilchos Geirushin 5:14
“Close to him” in the previous halacha means that the man could safeguard the get and the woman could not. If both parties are equally able – or unable – to safeguard the get, it is considered partially close to him and partially close to her.