Pollard was neither charged with nor convicted of treason. He was imprisoned for spying. Not the same. Also, Pollard coperated COMPLETELY with the prosecution in a deal which Caspar Weinberger cheated on. It is the US that has things to hide, not Pollard. This is why the US doesn't want to let him out!
Germany sends suspected ISIS recruiter back to Spain (AP)
from the article: Netanyahu to request Jonathan Pollard's release during Obama visit