Are you saying the Monster cables had red at one end of a single run and black at the other? That's the only way they'd be "wrong"....phase is relative. Just hooking up both ends wrong is fine. Also, adding any new components, especially amps and pre's can easily invert phase. Most tube pre's and some dacs invert phase. And many recordings have some or all of their mics wired wrong. It's not black and white. I used to worry about it, now I try and listen, and if it's obvious, it's obvious.
Worthless audio tip No. 347:
Note: an interesting thing about reversing speaker cable leads at the amp end (the easiest way to invert phase): When you do that, and hear a difference, the theory is that you are hearing the phase change (better or worse localization of mono signal in center postion, etc.). However, realize also that you are now asking the incoming electron traffic to go out, and the outgoing traffic to come in. Many will tell you that cabling is directional, especially well-broken in cable, and some of the audio changes are due to this.
Ted