I don't think that the math works like that. While it might take some time for an infected person in close proximity to push a specific second person across so

I don't think that the math works like that. While it might take some time for an infected person in close proximity to push a specific second person across some risk threshold in a 1-on-1 interaction, that's not the scenario we're worried about. We're worried about how many people an infected person might infect during many, many interactions. Even if the probability of infection is low in a single 2 minute interaction, some people in service jobs have thousands of interactions a day. (not all one-on-one).