mesader kiddushin

— Another potential reason for leniency is the basic requirement of weddings that the ring must belong to the chatan (Shulchan Aruch E.H. 28). In fact, mesadrei kiddushin verify with the chatan that he owns the ring and did not simply borrow it. If the chatan forgot to bring the wedding ring, the mesader kiddushin will ensure that the "lender" of a replacement ring transfers the title of the ring to the chatan with proper kinyanim (halachic mechanisms of conveyance).