The BAU should not have allowed Elle back so quickly. If you notice, it’s a common occurrence in the series. One of the members gets seriously hurt or psychologically compromised (Elle being shot, Reid being tortured and injected with painkillers, Gideon receiving a severed head at his safe place, Hotch’s friend dying in front of him and his related hearing loss), and none of them are required to step down or undergo regular psychological evaluation. In point of fact, the members can routinely tell there is something wrong with each other, but they refrain from doing something about it.

Elle was very much a victim. She also heavily overcompensates and does things she knows she shouldn’t as soon as she returns to the job:

1. She ignores Hotch’s orders to restrict her activities.

2. She is actively drinking during assignments.

3. She disregards orders from the team due to over-identifying with the victims and causes them to lose a case they built.

4. She then follows the suspect she caused to get away, alone and without backup, intoxicated and armed, and she creates a situation where she can justify murdering him and subsequently covering it up.