Question:
However, the sources of and motives behind cyber attacks often cannot be readily determined.

Does it follow that "The reason for hacks cannot always be ascertained."?
Answer:
yes

Question:
He stared unbelievingly through the crystal shell.

Does it follow that "It was easy to believe what he was seeing. "?
Answer:
no

Question:
If she made a mistaken bet that her husband could reform, she is now in the position of a Siamese twin.

Does it follow that "She was right that her husband could change."?
Answer:
no

Question:
You say you've recognized Number 1 to be Kramenin?

Does it follow that "You say you have noted Number 1 to be not Kramenin?"?
Answer:
no