Think ya just gettin lucky and the company has sucky (but good in ya favor!) testing... lol. They might have the stick testing (the kind parents can buy at the local pharmacy) and by drinking all that water, you just dillute your urine and pass.

Now if your company sent ya urine sample to a lab for testing, things may be different because they test for gravity, creatine levels, PH of the urine, etc. What may also affect it is ya body size, metabolism, how much you smoke and the strength of the trees you smoke.