Durrah (P) was employed as a special police officer by Transit (D). P was on duty and in violation of work rules left the guardhouse and purchased a soda from a vending machine D had installed in the employees' lounge on the premises. The violation was that D did not report that he was leaving the guardhouse and obtain a substitute to cover Post No. 1 in his absence. On his return to Post No. 1, P slipped on a staircase. He immediately complained of a knee injury and in due course sought benefits under Workers' Compensation. The ALJ denied the claim in that P had violated a workplace rule. The Review Board Agreed in that P knowingly violated D’s rules. This appeal resulted.