[ordinaryguy]

A freshly flushed toilet contains the same water the ice is made from.

Actually, there might even be a bleach tablet in the toilet (either hanging inside the bowl or in the tank if present). Without reading her report, we don't know whether the toilet water was sanitized with bleach prior to sampling.

[spunkets]

That stuff is usually colored. You're right though. The fresh water still has the hypochlorite from the city. Once the water is frozen, the Cl₂ is driven out.