Lol well I pretty much am a drug expert. cannabis anyways. CBD does not get confused with THC in the test. The reason CBD users getting positive THC test results is because they are using a massive amount of full spectrum CBD tincture or smoking tons of CBD flower which by federal law is allowed to have no more than like .05% THC which is minute but in large enough quantities will show up on a test.
The drug test doesn't even test for THC, it actually tests for a thc metabolite that CBD does not break down into.