From: Rabbi Moshe Sofer
To: Rabbi Yosef Yoel Deutsch
The Chasam Sofer reconciles the Bartenura's ruling that reliance on the Kohen returning redemption money invalidates pidyon haben with the Gemara's validation of matanah al menas lehachzir, explaining that the Bartenura follows a minority textual variant. He distinguishes three scenarios: no intent to transfer ownership (invalid), conditional gift evident from actions with Kohen intending to keep the money (invalid per Rema), and an unconditional gift with mere hope the Kohen returns it voluntarily (valid, and the accepted custom).
Source: Shu"t Chasam Sofer YD §290