The fact that he showed up for duty at Ops meant that he wasn't fatigued and was ready to go for the flight. Looks like he would have continued to fly if there wasn't an Alcohol & Drug test that morning.
Whether or not he would have tested positive, he forfeited that chance to prove himself when he ran off.
Indeed it would be interesting to see what the management is going to do, as this will be setting a precedence.