There are usually always two buckets of gold in Coin River. If the game ends, and then one of the buckets falls, it will not respawn. Nothing seems to be able to respawn it. I assume the gold bars will have the same glitch.
Be unlucky enough to have the time run out right before a gold bucket falls off of the edge.
The gold bucket should respawn regardless of if the game is in a state of being operated.
The machine was left handicapped by having one less gold bucket, a major source of tickets.