Casual Friday Confusion

We are working for one of those hip, trendy companies that has a "Casual Friday" policy. The spirit of "Casual Friday" is to relax some of the company rules so that employees will, for at least one day, forget that they hate the place (Hawaiian shirts are powerful). We are temporary employees of this hip, trendy company and today was our first "Casual Friday." We assumed the dress code would be relaxed and wore flip-flops and shorts. We were right. We assumed the rules on the page in the employee handbook titled, Alcohol, Narcotics & Firearms would also be relaxed. We were wrong... we are on probation.