It should be noted somewhere around these steps that all but one of these connections get removed.
The connection that is left goes to the Power Button, the Mute Switch, and the Volume Buttons. This connection is on the bottom left, below the LCD power connection.
This connector was not supposed to be removed, and I removed all of them as a force of habit.
Once removed, it seems I removed part of the other half of the connector along with the first half.
This has left my customer's iPhone functional, but none of the buttons, besides Home Button/TouchID), work.
In the long run, this is not a huge issue, as AssistiveTouch can emulate physical button presses. I just figured it should be noted.