[cameldrv]

If the false positive mechanism is contaminating one sample with another, the false positive rate will depend on the true positive rate in the samples that the lab/testing site is processing. The other possibility would be if positive control amplicon contaminated the lab, which does happen.

[pps43]

The underlying assumption behind false positive rate is that tests are independent and identically distributed. If in practice this is not the case, then false positive rate becomes misleading.