I actually had two PhD advisors [1]; Jim Woodcock and Simon Foster.
Both of them are legitimately wonderful and intelligent humans that I can only use positive adjectives to describe, but the one I was referring to in this was Jim Woodcock [2]. He had many, many nice things to say about Tony Hoare.
[1] Just so I'm not misleading people, I didn't finish my PhD. No fault at all of the advisor or the school.
I remember Jim Woodcock as really inspirational - he was working with my PhD supervisor in 1987. We were working on a variant of Z for specifying what, today, we would call CRDTs. I was also lucky enough to meet Tony Hoare the same year and discuss those concepts.