There are some horrifying stories of the virus transmitting from just fleeting contact. It can happen, but there are a lot of factors at play.
It lasted only a few seconds: One man walked past another man in a mall in Sydney. When officials later watched CCTV footage of the encounter, they saw that this was the only interaction between the two. But it was enough for one of the men, who didn’t realize that he was infected with the delta variant of the coronavirus, to infect the other.