On 04/10/2020 17:41, Nick Maclaren wrote:
I have just looked back, and "Most of the leaves were healthy; perhaps
a few have been a bit deformed." is stronger than I remembered, and is
flatly incompatible with Phytophthora (or Verticillium).

Yes, it doesn't look like Phytophthora or Verticlillium if the leaves
are healthy. I agree the spongy heartwood looks like a fungal attack.
Perhaps the plant was infected with more than one pathogen.

--

Jeff