Why not just wire nut it together and be done with it if it had protection? Essentially thats whats happened there. That is dangerous no matter whether it passed inspection or not.
Just because the part you pull out is clean and shiny doesn't mean that the rest of the connections are ok. A loose and/or dirty connection will draw more amps and create heat. Assuming that there is no reason for there to be fuses in that disconnect, ie another branch circuit, the copper tube is not a huge problem as you have discribed the situation. Breakers in the unit will not do anything to protect the wiring coming into them, only leaving them. That disconnect may have been put in there to kill the whole unit incase the elements need ot be pulled out as a asssembly like in many Trane units.
I couldn't just nut 'em given the large metal conduit coming to the d/c and another leaving the d/c to the unit. The only option was another d/c or junction box. I only had a d/c with me.
I'm at peace with it having redone it myself, all connections tight and clean.
But the lesson was driven home forcefully and will be heeded going forward. You only have to tell me...a few times. Maybe five. Six will certainly get 'er.