While I agree that humor has its place, Many people's coping mechanism is to make light of terrible situations through humor -which always comes across very callous.
I will say to you; just because you have more compassion than the rest of people in this thread; assuming they are wrong for cracking a joke is just as bad. People deal differently with trajedy.
The laws that they were investigating Clinton under require intent to harm the country, or gross negligence. The latter is a specific legal definition, which is more extreme than just negligence (which is what we all agree Clinton was).
Case history is pretty clear on the issue that it requires intent. No one has ever been convicted by a court for just accidentally removing classified documents, those people have only had administrative punishment. It would not be right to hold Clinton to a different standard than the other cases in history just because we don't like her.
This is the point Comey was making, which fell on deaf ears apparently.