Comment by AdieuToLogic

After having introduced an Easter egg and being called out for it, the author states:

  I became a cautionary tale though and would occasionally 
  warn off the new hires who might have had an inkling to do 
  something similar. And true to my word, I would tread very 
  carefully from that day on with an eye to what Apple HQ 
  would think about any of my actions — and potential 
  consequences (intended or not). 

It is very likely that management weighed the author's value to the organization against the cost, real or perceived, to rectify this particular situation. An additional potential value which was ultimately realized is the author became an extension of organizational policy "at ground level."

IMHO, this is an optimal resolution and should be applauded. Management reaped a 20-year reward and the author kept his job.