What a downer, Socks !  I'm sorry to hear that.
I think we're damned if we do and damned if we don't (in most cases of adults
who've well-thought out what they're going to do and what their limits are).
If we talk to them and they go ahead anyway, we feel we should have locked
them up, or dragged them to a psychiatrist.   There's always the "maybe a
better pill" or "maybe if we'd done XXX" feeling for us left behind.

I would think that if he had a bad case of MS, he'd likely explored
everything known to man to help ameliorate the situation and made a quality
of life and "control" decision.  Meaning that he'd set his limits as to what,
where and how his life would be and what he deemed intolerable for his
quality of life. And that plans were in place long before to NOT show danger
signs, so nobody would try to stop him or feel guilty and it still ends up
that way for those left behind.

It sure opens a "can of worms" when something like that happens, but
hopefully also opens lines of communication to discuss this issue and death.
You never know, his suicide might save someone else much younger who has not
thought things through carefully.

Hopefully the young ones will get some counselling. And perhaps at a later
date, they'll be able to celebrate the life of a man they admired. It's how
we lived (they say) is how we're remembered.

J