Although mistakes are made in the test-streets, if you follow instructions, the infection probability is low (but never zero)
Of course. Risk 0 doesn't exist, but in those places they take all possible measures.
I read some news that one nurse vaccinating against COVID-19 tested positive for COVID-19. They then tested all the people in the care center she had worked and found nobody positive.
That's an example of good procedures preventing contagion. She was wearing mask, gloves, protective eyewear, overalls, she broke distance from anyone for the shortest possible time, and it all worked.
I'm not worried about that. I mean that once you leave the test site you can cross someone who infects you, or you generally keep on with your life and keep your risk of being infected.
Since you know you can get SARS-CoV-2 at any time, knowing that you did not at a specific point in time is not that relevant about whether you currently have it, so it shouldn't be an excuse to be careless once tested negative.
Here's a nice factoid:
A study published in Nature Neuroscience shows how spike protein crosses the blood-brain barrier
www.labmanager.com
Bah. That won't scare me. If one single SARS-CoV-2 was in my mind I know I'd be finding naked pulmonar endotelium sexy and I don't, so I'm safe.

Seriously now, it's interesting but not surprising. It matches what the people I know with COVID-19 told me on the phone.
I guess they'll now have one more protein to use in brain drugs so that they can break the blood-brain barrier.