Ring pried from Carl's foot during treatment, its removal coinciding exactly with the accepted teleport.
During Carl's treatment for demonic infestation, Imani pries the toe ring off his foot as part of the procedure. Panford's adjudication footage pins the exact frame: the Accept Teleport Request prompt is accepted the moment the ring comes off, with Shi Maria in control of Carl's sleeping consciousness.
The timing is the hinge of the whole Field Ruling Adjudication — the instant Carl's protections were stripped for the cure is the instant Stockade's Summon Ally took hold.
A ring worn on the toe, removable only with effort.
The item whose removal marks the precise instant the teleport was accepted.