There is only one way - to invite some hacker and to give him that computer that person used to he try to find keys and passwords. I think such way is pretty possible.
Interesting idea but in the most cases, people around this person will have no idea about his Bitcoin.
Other financial assets of any person, are always recorded somewhere, and when person passed away, court, public notary or some other legal representative, will find out how much financial assets (money, houses, cars etc.) this person had and who should inherit it, according to the law.
Bitcoin is not financial asset, so nobody can inherit it.
In fact, Bitcoin is virtual and connected to the online or offline wallet, not the person.
So, if this person didn't trust anybody, and didn't share login info from the wallet, those bTC funds will be lost.