I don't think masks would have made a difference. N95 respirators yes, masks no.
Exposure load and time are the two critical factors. The exposure load is cumulative throughout the day. Since regular masks are very poor filters for particles the size of viruses you are still going to have a sizable load with no change in the time.
I also don't understand the , "they protect others from you" with masks. If they don't stop viruses from coming in how do they stop them from going out? You can look on the CDC webpage and see that they list them as ineffective protection from airborne viruses. Right along with the more moisture they contain and absorb the less effective they become, they should be changed often, they should never be re used etc etc etc.
The US health care system has been pretty steadfast in their opinion on anything other than properly fitted N95 respirators for as long as I've been around. Suddenly, because it seems like a good idea, they change their stance overnight. Won't even get into the recommendation to wear them outside in open environments.