No, but it means it is YOUR FAULT HE DIED! Had you not hesitated, our dear John would still be alive. You should be ashamed of yourself.
I really love hypothetical drama.

Prefer it endlessly to the real thing.
Now, to the matter at hand. Hypothetically speaking (and I hope that I never have to face the real deal), I'd donate marrow, sure. If it's someone close. A dear friend, a family member, a partner or spouse, it's all good. It might hurt like hell, but the pain of losing them would comparably be much worse and more long-lasting.
So it's still a matter of avoiding and minimizing pain, when you look at it that way.
Only nutjobs consciously run towards pain, or so I've come to believe. If there's no trade-off, what's the point?
So finally, to answer the original question- no I wouldn't.

Because that would mean that I'm doing something wrong. If you ain't fucking up and getting burnt occasionally, that means you ain't striving, and that's a sad, sad fact.
Of course, if you mean it in the sense that if I could magically whisk away all the consequences of my fuckups, breakups, losses and defeats, would I do it?
Then my answer would still be no.

Sorry. We try to avoid pain, but it's there to teach us a lesson, every time we get hurt. It toughens us up, if we're smart. Gives us a thicker hide and a cooler head. And that's always a plus.
And if you're asking us if we would like to live a pain-free life in the sense of a life filled only with joy and butterflies and pink elephants...
Well, the Christians beat you to that concept. It's called heaven and you go there when you die and I'm happy to state that I'm not fucking dead yet.
che