I'd not throw insults unless the figure that he quoted was actually
wrong.
At a guess, he compiled statistics by hand. If I was in his position tackling that task, I'd have first thought of tackling it that way, and also likely would have stopped with a single day's data.
The fact that it is more convenient for you to gather data is no cause to be insulting if a longer time sample disagrees with what his sample indicated. If you can show that he miscollected or deliberately misrepresented the facts that he presented, that might be different. But that isn't the situation here.
