not meaning to bash u or anything but why not just take off the lid its much better like that
Wrong. Its possible to choke an engine, even when jetted correctly. The CLEANER the air, the better it will run. Also, with that lid, it will shed the minimal amounts of water that make it to the box. rather than it just laying in the box and splashing back onto the filter.
the whole point being is there is nothing wrong with what he did and you had no right to tell him otherwise.