This can actually be solved using smart contracts in bitcoin, it is built into the underlying bitcoin opcodes -- CSV https://github.com/bitcoin/bips/blob/master

This can actually be solved using smart contracts in bitcoin, it is built into the underlying bitcoin opcodes -- CSV https://github.com/bitcoin/bips/blob/master/bip-0112.mediawiki https://github.com/bitcoin/bips/blob/master/bip-0112.mediawi... This is the underlying mechanism for Unilateral Channel Close in the lightning smart contracts (on bitcoin), a timeout spend clause. Note: It wasn't a thing when these coins were first acquired, so it doesn't really help in the situation.