Nah. I think she was careless on purpose. Imagine if she transferred it using encryption and Russia got ahold of it, and then claimed she gave it to them. I think she wanted people to know so that she could claim that she was doing the right thing.
A jury (with nullification power), in principal, might (as might the electorate who choose Presidents who have pardon and clemency power); if you aren't going to flee to avoid capture and aren't confident of your ability to evade the counterintelligence services in the long term, compromising your ability in the short term to improve the optics of the event may not be completely irrational, even if it is far from guaranteed to pay off.
I've not only been on juries, but studied them. Nullification is a thing. It's quite rare and unlikely in the specific circumstance at issue, but that's already factored into the discussion in the grandparent post.