My condolences Bruce,
I'm originally from Iloilo City, But I've been in Manila since 2001. Cebu is pretty close to home. And i've had a similar experience but it wasn't in training. And luckily my father made it to the hospital and survied. It was his first stroke. I understand that fear all too well.
If you don't mind me asking, ilang taon na siya?
It simply may have been his time. I believe that tho you tried everything you could it probabbly wouldn't have changed the situation.
Give it some time, Im not sure if taking a short time off from the Dojo will help you, but thats the best advice I can think off.