I'm a little disappointed that the article doesn't mention a serious practical impediment to nullification - the "voir dire" process of juror selection. They ask you a series of questions, one of them usually being "Will you apply the law as I explain it to you?" You are 100% within your rights to answer no - they'll excuse you from the jury. If you say "yes", however, but you mean "no", then you have committed perju…
I've done jury duty, they ask me no such thing.