I don't know him, or his situation but I do know very well the contractual terms for workers in the NHS and the complaints processes for the HCPC along with other regulatory bodies. So I know if there's any kind of formal complaint or disciplinary process that in and of itself would prohibit him from contacting you. I don't know if his employer has started such a process or not but it's one reasonable option, out of many, that would explain why he hasn't replied to you.

And I'd expect an advocate with 30 years experience to know that death or coma aren't the only reasons for ending a course of therapy in an untimely way.