He should have filed charges and had him arrested! This is Kansas law...
Harassment of/Interference with Service Dogs
Inflicting harm, disability or death to a police dog, arson dog, assistance dog, game warden dog or search and rescue dog is a nonperson felony.
Penalty of not less than 30 days or more than one year's imprisonment and be fined not less than $500 nor more than $5,000. The person convicted shall not be eligible for release on probation, suspension or reduction of sentence or parole until the person has served the minimum mandatory sentence.
K. S. A. 21-6416