Seems likely.

that one must have hybrid vigor

I just knocked on the door & talked to the owner. He told me about it (he was proud of it), and had planted numerous nuts from it around his house. Here's a closeup of the trunk:

That's a pretty spreading crown for a walnut, isn't it?

This one is a homestead remnant in Kingston, Ontario. It is on Ontario's honor roll as the largest Black Walnut in the province. It's 6' in diameter and 90' tall.

Unfortunately, the exclusion zone during big box store construction 10+ years ago was too small and soil compaction is causing a long and slow decline.

{{gwi:362118}}

Here is a link that might be useful: Ontario's Honour Roll of Trees