Reading the code did not catch it. Reading the output did not catch it, because the output was a lie told honestly. The thing that catches it takes four seconds:
Go and look at what it made
Open the folder. Count the files. You asked for five and there is one, so it is wrong, and you knew within seconds without understanding a single line.
That is the habit worth taking from this page, and it works on everything, not just code from an assistant. Your own programs will lie to you in exactly the same way. A program telling you it worked is the program's opinion. The folder is the fact.
What to do when you catch one
Go back and say what actually happened, not just that it was wrong. "It printed saved dog five times but there is only one file in the folder" gets you a fix. "It doesn't work" gets you a guess.
Describing a fault precisely is most of what fixing things is. You are now doing the part of the job that does not go away.