Actually the US Constitution defines treason.
Assuming you believe in the US Constitution- Pollard in not guilty of treason.
The criteria used by the intelligence community is placing classified information outside U.S. control. Once outside U.S. control, it is effectively compromised. Pollard provided information to Israel, who could have bartered it to China or the Soviet Union.
It was not for some junior analyst to decide our intelligence collaboration with a foreign country. Pollard's attempt to do so was treason.