Obviously you're asking a non-trivial question... but there's one thing we do know for sure: Pollard did not take the information that Weinberger thought he had. Sabramerican also posted a relevant Weinberger quote.
I have a hard time believing that the U.S. Secretary of Defense submitted a secret legal brief to the Federal court in the Pollard case based on what he "thought" Pollard had given to Israel.
And if Weinberger eventually concluded that this was all a mistake, then why was he never called as a witness for Pollard in any of these subsequent appeals?