Offizieller Kommentar
Yes, the issues between scratching and pitch bending would be related -- the difference between the two actions is simply "is the jog switch pressed?" and if so, it scratches instead of pitch bending.
Unfortunately we can't provide any information or instructions on disassembly or repair as nobody here is authorized to provide you with those details, regardless of the desire to potentially damage your mate's player. ;)
Please contact Pioneer DJ technical support in your region to have your hardware inspected and/or serviced.