Impact of MacNeil on Unemployment Benefit Eligibility. 
In MacNeil, an employee was subject to random drug and alcohol testing under the employer's substance abuse policy.  The employee tested positive for marijuana and was terminated.  The employee filed for unemployment benefits, which the employer opposed. 

The employee argued that he should be eligible for unemployment on several grounds.  First, he claimed that the employer's substance abuse policy did not specifically prohibit off duty drug use.  Since there was no evidence that the marijuana was used on Company premises or during work hours, the employee contended that the policy was not violated.  Second, the employee argued that, despite having some indication of marijuana in his bloodstream, he was not "impaired" and, therefore, was safely performing his job.  There was no objective evidence that his work performance was unsatisfactory at the time he was selected for the random testing.  Finally, he argued that even if he tested positive for marijuana, his off duty drug use did not rise to the level of a "willful and substantial disregard" of a fundamental expectation of his employer and, therefore, did not constitute "gross misconduct" under the unemployment rules.  He argued that, since his use was not connected to work, the fact that marijuana remained in his bloodstream was simply "negligent" at best.  He claimed he did not intend to violate his employer's policy and believed that the drug had left his body before he reported to work.