If the Bitcoins do get spent sometime later, you could argue someone likely bruteforced the passphrase (it was only 12 characters long). That's still reasonable doubt.
Good luck arguing that that a password with 78-bit entropy (12 characters out of 95 in the ASCII set) was likely broken by brute force. 'Reasonable doubt' does not mean 'no matter how improbable,' otherwise nobody would ever get convicted.
Reasonable doubt means there is reasonable doubt. Or if you prefer metaphors, the term is naked. Doubt, that the progenitor of the pass phrase was likely the one who transferred the coins to another address(s) is sufficient to preclude it as a determining factor. That is, of course, if your lawyer is good enough to be persuasive.
Meanwhile, people have been convicted with far more implausible evidence (eyewitness testimony comes to mind) so this will be the least of your worries.
You tried to infuse more meaning to that term by trying to add to its definition a-thing-that-it-isn't.
>'Reasonable doubt' does not mean 'no matter how improbable,'
You're right. "Reasonable doubt" also does not mean "Ice Cream Sunday", but that doesn't make it "Pudding" instead. The term means exactly what it says, so I say again, "Reasonable doubt means there is reasonable doubt".
It's times like this I genuinely wish HN had an "ignore" feature since I don't believe in down votes.
Good luck arguing that that a password with 78-bit entropy (12 characters out of 95 in the ASCII set) was likely broken by brute force. 'Reasonable doubt' does not mean 'no matter how improbable,' otherwise nobody would ever get convicted.