Under any established institution of law Courts may presume that police have carried out direct orders of its chief commanding officer. Military courts have construed that insult, disrespect or disobedience to any officer is an offense towards his or her individual rank extending as high as the chief commanding officer.
In essence spitting in the face of a police officer is equal to tossing a shoe at the President. The punishment therefore may be more severe than apparent.
In reference to intoxication that may not serve as a defense. The Court may construe that the party has willfully through volition chosen to consume a mind altering substance (e.g. alcohol etc.) that has led to his or her own intoxication.
Probation may compound matters because punishment or sentence has been suspended to permit a convicted party demonstrate his or her aptitude to remain out of trouble. Violation of probation may lead to termination of the suspension.