I know post after post says that gender isn't ever tested during drug test but why do I find this on the internet?

9.2.1 Urine from a donor
You can substitute someone else's urine. Gender and approximate age of the sample can be detected, so take care when choosing a urine donor.
And where did you find this bit of false info?

Edit: Nevermind. Whoever makes false claims like these need to do some serious research of how drug testing works and how the testing methodologies work. Because if they done their research, they would know that drug testing devices are unisex - they have no ability to determine the gender or age of who the urine sample came from.