Let's go back to https://news.ycombinator.com/item?id=35473227 and see what was said.

> ...I would copy their db onto my Mac, run the mongler on it, and then I would take the database home with me, without worrying whether the theft of my Mac could lead to lives being ruined.

From that, it was definitely run against a copy of the database.

The code that you showed looks like PHP display code. So it will change what is shown to the user, but unless showMixedFruit is horribly misnamed, will not change what is in the database. And therefore does not address the problem that the mongler was trying to solve.