Apprentice fits his first toilet but something went wrong

This apprentice plumber has a lot to learn yet. Yes, he perfectly putted on his first toilet but something seems to be wrong. Can you spot it?

The door. He forgot to shut the door before fitting the toilet.

In reality, this is not a really big problem, he just has to remove the door hinge pins and pop the door off. But it should be frustrating to make such a silly mistake for a first time!

Watch it in video: