Tenson & BD,

You'd make much more progress in this argument if you stopped loosely using the word "distortion". You're really arguing over three things:

noise - is not a signal related component. (eg RFI on balanced cables).

distortion, is signal related (it's the thing you're distorting), and you can split distortion into linear and  non-linear components:

Linear distortion, by it's very definition can be corrected - parametric and graphic equalizers are linear for instance, and most other (competantly designed) electronic devices are linear and minimum phase. So, if you don't like what the studio did with their parametric equalizer, then you can undo it with another equalizer.

Non-linear distortion (clipping of a signal, addition of harmonics etc) can not be generally undone.