2 thoughts come to mind:
1) Apparently the sentencing judge was bluffing when she promised Dennard time behind bars on a 2nd violation (first was for DUI). Considering the fact that both violations were for alcohol related crimes, you don't see a 3rd chance too often without some type of intervention. 5 days behind bars just isn't going to cut it.
2) I repeat again--It is VERY difficult to fail a test for alcohol, since it's processed at an ounce an hour. You can basically drink 8 beers from the evening until 2 AM and still pass a test around 8-9-10 AM. This means that he was basically intoxicated while giving the test(s) in some capacity. His probation officer obviously isn't showing up at 4:00 in the morning, which means that he could've easily continued to drink had he been slightly more responsible.