The code isn't a Monte Carlo simulation if you read it. It just iterates until it's simulated every day of the epidemic with the input seeds and then outputs the results to a table. The results are then given
exactly without any uncertainty bounds: to make it a Monte Carlo simulation is probably impossible given how slow it is.
I think the article author mentioned that just to show (s)he understands stochastic modelling. As can be seen from your comments and others, it's apparent some people/scientists either aren't reading the article properly at all, or have a massively wrong understanding of what Monte Carlo/stochastic modelling techniques really are.