Man this has to be an absolute joke. I already said:
Can you please spend a few minutes to think things through before you reply?
You ignored that, obviously. This is basic statistics. Finding 5 in 1000 while also false detecting 6 others is NOT less than 50 % accurate just because 6>5. it is 99 % accurate. Not to mention that they might still indicate correctly, just that the person does not have a relevant amount on them right now e.g. already used it.