Exactly this! I got a visit from children’s services the day after I came home from the hospital with my baby. The reason? The urine drug screen submitted from my nurse was taken from my catheter 2 hours after my C-section so I was positive for benzodiazepines and opiates from the surgery. I had no idea until the case worker was in my living room. On her paper I absolutely looked like I had a drug problem, but that was not my reality. Plus, the baby tested negative for those drugs at birth which did strengthen my case.
But she interviewed me and my husband, looked around our house, and was satisfied until I could get all my medical records sent to her office. DCS was satisfied that we were adequate if not good parents and the case was closed in a few weeks. It absolutely sucked and really ruined my experience as a new mom. But at no point did I think this woman wanted to take my (much wanted, very loved and conceived through fertility treatment) baby from my safe and clean house and loving family.
I personally know people who have had their children taken away and as much as they are like “we did NOTHING wrong” in every case there has been serious issues. There simply aren’t enough resources in the system to take lots of children without real cause.