A lot of the episode was dedicated to guilt and shame. At a certain point, it became obvious that the writers were building tension, forcing the viewers to confront these feelings, even if it made them feel ill at ease. It was such a relief when Tuello showed up at their house near the end.
Out of everyone, he seemed the least likely to understand June's actions. He had a crush on Serena in the earlier episodes, and he was conned into taking part in the murder. He didn't seem very happy to go along with June's plans even before he realized that she was going to kill Fred.
But surprisingly, he understood. He told June that she did a horrific thing, but it had to be done. This was after he saw that Fred's pectoral had been ripped off. He also understood that her actions came at a cost, seemingly referencing the shock that June was facing at home.
June's relief must've been felt by the audience as well. In the end, she did the right thing, and it seemed as though she needed to hear that to move on. Whether or not the dynamic in the household will change is yet to be seen. In the trailer, we see Rita warning Moira about June. So there's bound to be some type of conflict going forward. At least we know June will be at peace with what she did. That matters.