What could cause false positive urinalysis results for cocaine?

I once got a false positive that landed me in jail. I began taking a human growth hormone in pill form, made by Ultra Labs, in CA. That same day I was tested for rehab and was thrown in jail for a positive result for cocaine, it was a probation violation. I don't do drugs, and I sure as heck didn't do coke the day before I was supposed to go to rehab. I'd only begun the pills because the rehab offered a free membership to the gym for the six month program, I wanted to cheat a little, so I began the pills, followed by two glasses of orange juice. That was all I had that morning, three hours later I tested positive, and even though the sample was sent out to an independent lab, it still came back positive. So, beware, many supplements, especially creatine, and taurine, will make you test positive, as will most energy drinks.
What a bunch of BS. I am a testing tech and will tell you that I have tested thousands who have used energy drinks and never had a positive for coc.