So you are speculating.
Was it the mask that made the difference or that he was symptomatic?
How would you know that you didn't get it from a different person via asymptomatic transmission?
Speculating?
1. He was at work Thursday,
2. He was sick/ Everyone told him to go home
3. He was coughing profusely he had a fever, and he did not look well
4. He tested positive for covid that night. I found out the next morning. One girls was sent home as a close contact (she sat next to him all day) although she just returned to work 2 weeks earlier from her own severe case of Covid 19
5. The rest of us were not considered close contact because we were more than 6 feet away and we wore masks.
6. I was not around any other people since tuesday night when my wife left for her trip
7 . The other two girls just returned from their own cases of Covid 19. I was the only one in the office who had not had it.
8. They say three to 4 days is the exact time it take to star showing symptoms My first symptom appeared sunday, which was three days after. I tested positive 4 days later.