I don't suppose "Knob and Tube" rules would appy here... You're suposed to use tubes of "loom"? to protect the wires from the connectors on the boxes... ?
He, the HO decided that this was beyond his capabilities so he hired a EC to correct this situation and it was corrected. Previous to the picture posted, there we no boxes and three conductors to the panel with the neutral splitbolted to a 4/0 green conductor and the ECG cut off at the SER jacket. Didn't have a camera that day.
What about Sections 300.3 and 300.30? Wouldn't splicing those conductors in the manner shown lead to the heating up that metal box containing only a phase conductor and a ground?