Not just possible... If someone does not take care, the can switch any of the conductors in a wire. Is it fixable? Yes, but it depends upon how the cord was constructed. Sometimes the inside of the plug is filled with silicon or epoxy, etc... If that is the case, if you can not satisfactorly clean it out, you would need to buy a new plug (or plugs). Then there is the issue of whether the connections werre soldered...
Ground Question-Power Cords
On one of the power conditioners I own (counterpoint Pac5) has a feature where it will diagnose the status of the electrical line..open hot, open neutral, open ground, hot and ground reversed, hot and neutral reversed, and correct...Ive noticed that when changing after market power cords into the PAC 5 the status changes, a cord I have has a neutral and ground reversed, is this possible and is it fixable? Would this create ground hum problems in the system? Thanks for the feedback!