Loose end tied up

Over the years I'd often idly wondered whether or not there was a connection between my BAIN ancestors from Caithness, and those of a BAIN family with origins supposedly from Caithness, who lived in my childhood district (Central Otago, NZ).
Failing a connection to mine, what about one to the other BAIN family who also arrived in Dunedin about the same time, give or take 10-20 years, in the 1860s/1870s?
Attempts at connecting the latter BAIN family, that of William and Jacobina (MANSON) BAIN to my BAINs had failed, but we did end up connecting them, distantly, by the MANSONs.

The Central Otago BAINs worked back to a William, butcher, brought up in Kaikourai, Dunedin, emigrating about 1857 from Wick with his parents.
His marriage certificate said his parents were a George & Jessie BAIN and the most likely candidate was George Traill BAIN in Dunedin, BUT George and Jessie hadn't married until 1864, which didn't really "fit".

This week an idle web search brought up an article in the Otago Daily Times (the Dunedin paper) about a BAIN family reunion last year for descendants of George Traill BAIN and included a snippet that George had emigrated with wife Elizabeth, dtrs Catherine and Margaret and son William, in 1862 on the Silisia, wife and an infant dying on the voyage. George's cousin Janet later coming out to look after the children, and then marrying George.
Bingo.
This was sufficient information to identify the likely family as being that of William BAIN & Catherine SUTHERLAND of Thurdistoft (1841) then Tain (Catherine, 1851).
A fellow member of the Caithness Family History Society's message board had provided their 1841 census details some years ago, and it included Margaret, Catherine and William, of the right ages.

After all that it doesn't look as if they're likely to match my BAINs of Latheron (Clashscribie), but it was a satisfying loose end tied up.

How lucky can you get?

Genetic genealogy, aka using DNA testing to (dis)prove theories and relationships between family trees, can be the luck of the draw.

Does anyone actually still exist that would be eligible for the appropriate test?
Has anyone with the right surname and genes tested yet?
Were the any mishaps down the generations between the shared ancestors?

You may recall the story of what happened when I voted at our local body elections a year or two back.

There is now a sequel.

Since then John has been back to England and met up with some of his newfound maternal grandmother's relations, but the GOVIER connection was still unproven/unsolved.  Was he actually a GOVIER by descent or in name only?

DNA testing, and a match to a GOVIER descendant of the Pitminster (Somerset) GOVIERs would be a great start to confirming that his step-grandfather was his actual grandfather despite the grandparents marrying in the year following his father's birth..

Along came a suitable price reduction in the entry level test for Y-DNA. This was enough for John to venture forth, with a bit of prompting. We had even found a couple of potential candidates from the Pitminster line to contact if necessary.

He was cautioned that at 12 markers it was more likely that he would get a number of matches from a variety of surnames, and that it really was only the start of the process, unlikely to be at all definitive given that such matches share an ancestor hundreds, if not thousands of years ago, rather than within genealogical time frames.

The Y-DNA12 results arrived today.
How many matches - one.
Surname - his.
Most distant ancestor - the same William GOVIER of Pitminster Somerset.

I'm not sure I want to suggest further testing and see this match fade away as the markers increase!