transferred-missed.js

const xs = [
  {
    agent: 'Jon', ring_time: 1, queue_id: 1, talk_time: 0,
  },
  {
    agent: 'Jon', ring_time: 1, queue_id: 1, talk_time: 0,
  },
  {
    agent: 'Kayla', ring_time: 1, queue_id: 1, talk_time: 1,
  },
  {
    agent: 'Jon', ring_time: 1, queue_id: 1, talk_time: 0,
  },
  {
    agent: 'Myke', ring_time: 1, queue_id: 1, talk_time: 0,
  },
  {
    agent: 'Dan', ring_time: 1, queue_id: 1, talk_time: 0,
  },
];

function getMissedTransferLeg(legs) {
  const i = legs.findIndex((o) => o.talk_time > 0);

  const res = legs
    .slice(i + 1)
    .filter((o) => o.agent && o.ring_time > 0 && o.talk_time === 0);

  return i === -1 || !res.length ? {} : res.at(-1);
}

console.log(getMissedTransferLeg(xs));
// { agent: 'Dan', ring_time: 1, queue_id: 1, talk_time: 0 }

console.log(getMissedTransferLeg(xs.slice(3)));
// {}