Thats what i dont understand. You have incomplete information. Yet you are saying what is what and what information we should listen to.
I dont understand why you mentioned earlier, as an example, that DNAs take 3 days+ so doctors can only take visuals. Not true, they take gram stains too that shows up the same day, if not before you leave. The guy said he had a DNA test (probably a gram stain) yet you refuted it.
I just dont like the overconfident trust me im a scientist tone. Would be much better if you said the risk is low but it can happen but i cant accurately guess the size of the risk. Because it does happen. But it is low.
Chlamydia doesn't work for a gram stain, gonorrhoeae does, but from a swab that takes time to culture. With DNA tests there is time to send them off to a lab and then get them back, hence 3 days, the PCR for amplification takes time, anywhere from a few hours to 24 hours depending on what you're looking at. But you won't get DNA the same day, you'll get that result 3 days plus.
Addiontionally for Chlaymydia and Gonorrhoera they recommend a 2 week waiting for retesting to ensure it the drugs have cleared it from your system. That's basic NHS guide lines, testing before then may pick up traces of dead bacteria and lead to a false positive.
I've worked in labs with various cell lines, human to viral, bacteria takes time to grow for gram tests, it's not instant. Easier to do DNA from urine than cultures. The pcr will show more for a definitive result from a liquid.
These are just the realities if the time scales, you may pick up something in tests same day, but that's only if someone has a significant infection (more than a few days/few weeks depending on the STD). There is the prick test for HIV but it is still lower reliance at determining early contraction than a vial test.
And I've repeatedly said it's a theorised risk, but we have no numbers for it as we have no proven case studies. Without proven case studies, then I question. But with clauses. Maybe it's true, but body of evidence isn't suggesting it. However science is theories, true until they're categorically proven otherwise.