Its very easy for someone stealing important documents to say that the purpose was to whistleblow. One of the issues before the Court will be to judge the veracity of that defence. The whisteblowing justification may not be a defence but may well be relevant to sentencing. It sounds from the tenor of the article that a judge has some doubts about the whistleblowing explanation but we will eventually see.
12 Iraqi troops, militiamen killed in multiple ISIS suicide attacks (AP)
from the article: Anat Kam: I stole IDF documents to expose West Bank war crimes