There is an area of "judgment" wherein an officer has some latitude to issue a citation, give a written warning (in some jurisdictions) or simply give a verbal warning.  The criteria applied is often a source of dispute.  This is where questions of "racial profiling" or "socio-economic class preferential treatment" arises.  This is where preferential treatment can come into play.

IMO, Chief Kerns chose the "honorable path" regarding his son's actions.  He could quite easily have handled the incident(s) as a parent and within the family without involving the police (in this instance, because of his position, the State Police.)  To have done so would have meant a conscious decision to "issue that verbal warning" rather than take "legal" action.  It would have entailed "preferenctal treatment" for his own son.  Chief Kerns chose not to engage in such preferential, but to report the incident(s).  

You have stated that displayed a lack of "family loyalty."  I disagaree.  (cont.)