Suppose there are 2 candidates up for a position. The faculty votes and they each get a positive but borderline vote of 30-18. Most deans would not know what to do. Don't misunderstand, it's not about the candidate but an assessment of which group is safest to piss off. Now you may be thinking. "But it's 30-18, Isn't it easy." Wrong because in that 18 maybe the pals of the dean or at least those likely to make him or her most miserable if an offer is made.
So, unpacking starts. If you are in the 30 and are worried about an offer not being made, the argument is to identify the likely no votes and say why they voted no. For example, there were 18 no votes but some of those were based on racism or homophobia or disagreement about the 1st amendment. All of this may be true; then again it may not be. Deans in particular unpack votes to get the outcome to please those most likely to be troublesome if they are not unpacked. They do not unpack them, even of the numbers are the same, unless pushed.
There is another form of unpacking that is post vote knit-picking. For example, a candidate comes in and gets a decent positive vote that ordinarily would lead to an offer. The problem is that those in the minority do not want this candidate. So, the picking begins. Remember this is after the vote and the arguments are made to the dean. "I looked at Mark's footnotes and I can't believe he did not cite Jack Bauer." Deans do not go to the 35 who voted yes and ask if they were concerned about leaving out Bauer. To those 35, after all, the game is over. So the 18 or 10 no votes become heavily weighted because they begin unpack their own votes to suggest they are better informed than the others.
I've seen some unpacking lately and I am not sure what actually should happen. Some people do vote one way or another for irrelevant or even wrong reasons. The problem is that all the votes are tossed out when the unpacking begins, even those of people who had the right reasons.
One solution is for each person to state his or her vote and why. If you think law professors would ever do something so transparent, I've got some Florida swamp land we need to discuss.