Question: Has anybody out there laid solid oak strip floor over a 3/4" particle board subfloor and lived to tell about it?

Basis for question: I did a search on SE and all answers point to pulling it up, block the walls if needed block the edges where the new will tie in, etc. All of that is proper and good, if I was doing this in an empty house, or even my house while I was living in it.

This will be done in my aunt and uncles house, both are well in their 70's and I will not disrupt their lives that this would require. I called the flooring manufacturer customer service, and I was told the engineered flooring could be stapled down but the solid 3/4" could not. I guess wood movement or lack of it has something to do with it, but I could not quite put my finger on why one is good but not the other. So I asked the customer rep the same thing. The only response I got was, ask this of other installers out there that have done what you seek to do.

So here I am, I know it is frowned upon, but nobody has said in the forums it has failed, only that it is not good to do and the subfloor needs to be replaced. So as an extension of the question is, has anybody installed solid wood floor over a particle board subfloor and it failed, even in the slightest? I do understand that if the floor gets wet there will be problems. The house was built in the 60's and the floor is still solid everywhere I checked, there are vents in the floor I removed to inspect under the carpet the amount I could lift up the carpet to look under where I could.