A destiny point can be flipped for things you could reasonably thought of before hand or in the area the character is in. IE you could flip a dp for a breath mask in a space station corridor. but not in the jungle. With utility belt talent you can still do it in the jungle.
I prefer my own adjudication, for the reason that those things you could not reasonably thought of before can cause the game to grind to a halt. That's what deus ex machina is meant to avert.
On the other hand, rules-lawyery players can - and will - make the case, at ridiculous length, why their character could have foreseen the need for said item. That's also a debate that grinds my game to a halt. I'd rather move on with the game than think if the characters could reasonably have thought of thinking the think... thing.