Publication errors, changes

[Jim Flanagan]

No: HPFGUIDX 8597

There seem to be more and more unexplainable discrepancies and 
changes being detected recently.  Some of these include:
  - pee vs. loo in CoS American & British editions
  - missing paragraphs about the flying car in the Br. ed of CoS
  - the clunky wand-order redaction *within* the same printing of GoF
  - ancestor -> descendent -> ancestor flip-flop

My question is for anyone with insight into the publishing biz:  Are 
these changes likely to have been authorized by JKR, or is the 
publisher most likely acting unilaterally?  What are the customary 
practices in the publishing industry?

-Jim Flanagan