Double standards

So the other night at work I hit a sign with my snowcat. The corporation I work for has a $500 tolerance policy. In other words anything over that amount you must submit a urine sample for drug testing. I am one of the lucky ones who gets to go pee, no big deal I'll pass no problem. Where my question comes in is in the past two weeks there have been two other people who have done more damage and haven't had to submit a test. What makes them so special? Why can't people hold standards to everyone except a few? I understand the fact that I messed up but when other mess up they should be held to the same rules as everyone else. It is almost a discrimination thing. I just don't understand it. I wonder what the labor board would think. I would never go as far as to report anything this minor but I feel like I'm being singled out and that is just unethical and very wrong. I just don't get it. I think it may be time to move on to something else for next winter ski resorts just have way to many issues.