How can a Bitcoin Oracle ensure that the money can't be respent? Suppose I modify the requirements of the Inheritance Scripting Sample where I need to make sure that the prior BTC is "guaranteed" to be available and not reduced or re-spent prior to either of the preceding events:


The 18th birthday arrives
The oracle verifies that the man is dead


With the additional requirement that the Oracle can't hold the transaction hostage for a ransom (since it would know how much is due to the payee), is there any way to use scripting to cover the condition that the previous funds can't be respent?  How can this be done?
(elaborating on the comment I gave to the question)

You do this by wiring the funds to an address controlled by both you and an oracle (or a set of oracles). You do this by utilizing a bitcoin multisig address.

That way there's no way for you to move the funds away without oracle's permission, and there's no way for oracle to run away with funds.

As for preventing oracles from holding the transaction hostage, you can use distributed oracles - i.e. a set of independent oracles. So, to withdraw the funds you'd need a signature of both yourself, and say 8 out of 15 oracles. If you choose oracles wisely, the chance for them to collude and hold your funds for ransom should be minimal.

You can consult Orisi Whitepaper ( https://github.com/orisi/wiki/wiki/Orisi-White-Paper/ ) or website (oracles.li) or github repo (https://github.com/orisi/orisi) for more info.