Absolutely, if the sun is able to penetrate (the container is UV transparent i.e. plastic bottles) and there aren't large clumps in the water which protect the

Absolutely, if the sun is able to penetrate (the container is UV transparent i.e. plastic bottles) and there aren't large clumps in the water which protect the pathogens from exposure. Which would make a packed bed filter a reasonable pre-filter before bottling and leaving in the sun for a number of hours. However, that wasn't what he said in the video, which was that the water hadn't been tested but was probably safe to drink.