Still surprised I got voted down for that, since C and Java are still correct.
In fact, it's what I hated about Java web development the most... You had to compile, package, and deploy every time you made a tiny change. It was a nightmare.
The Play framework uses its own copy of the Eclipse compiler to compile everything on the fly while it is running in development mode...so as you as you save your changes, you can reload your browser and see them immediately.
Doing a tested change and then a pushing to production is a 4 command overhead using git as lazily as possible with maybe an additional 5 minutes spent during initial project setup. You're doing the same coding work, you're just helping to ensure it's not going to create any completely useless work spent undoing mistakes. It's an ounce of prevention, pound of cure argument in my mind.
This all depends on what kind of site it is, of course, but in the context of what he's saying, it makes sense.