>>10403999 (lb)
This is...ignorant The sequence in question needs to bond with the primers--in other words, the nucleotides need to pair with the primer to create a 'false positive' which is what you're alleging.
So where a primer would be something like
ATTACGGCGATTT
the corresponding sequence would be
TAATGCCGCTAAA
And then you have the complication of narrowing down whole sections of codons (series of nucleotides that actually code for transcription/translation) and 'bracketing' the target code with the second primer sequence.