"We were transferring fruit a lot, from the boot of our truck, or a trailer, into these fruit bins."
He said his finger must have shrunk a bit over the almost 62 years he has been married to his wife Shirley, because the ring was a bit loose.
He was annoyed and disappointed when he realised it had disappeared.
"Because, actually, I have lost it before," he laughed.
In fact, the ring has disappeared from his finger a total of four times, once while throwing rotten potatoes into a field during his tenure as principal of Pakowhai School, once while gardening for his daughter in Wellington, and another in a chair at home.
This time, after retracing his steps on not finding it, he contacted the Dunedin East Rotary Club, where four boxes of citrus fruit he had packed was headed.
"We got a call back saying they had packaged all the fruit, ready to go out, and hadn't found my ring."
Hopes still high, Alexander said he thought it could have ended up in another lot of fruit being shipped to another area of the South Island.
About three days later, he got a message saying Timeless - which had sorted the fruit in Dunedin - had found a ring in its driveway.
"They sent a photo back to me and of course, it wouldn't have been any other silly person to have lost a ring down at a truck yard down in Dunedin."
Ring finder, Timeless owner Barry Johnston, said he noticed the ring sitting on the driveway, because it was a different colour to the surrounding gravel.
He imagined the ring had got caught in a gap in the fruit box, which was why the team did not find it while unpacking the fruit.
He said when the team was clearing the boxes, it must have fallen out on the driveway.
"Later that day, there it was amongst the gravel. He was just bloody lucky."
As for Alexander, he said he was grateful to the team at Timeless and the Dunedin East Rotary Club, for finding the ring and sending it back.
He said his wife Shirley was also grateful to see the return of the ring, joking he would not "run off and find someone else now".
He remembered being told if you lose something and are meant to have, it will find its way back.
"That's certainly happened this time at any rate."