Even if we stop focusing on the definition of what "throwing a fit" actually means (to become extremely excited or angry), it's still kind of unfair to take this whole moment out of context.
We have to remember that Justin is an artist. Perfection and specificity are important when it comes to personal work and self-expression. If he's been working hard on his appearances and performances, it's understandable that he'd be upset when an aspect of it didn't go the way he'd planned.
It's also worth noting that there is no background information to supplement this exchange. It's entirely possible that Justin had talked to the cameraman beforehand or requested more room to properly execute his choreography. Let's all take a deep breath and cut him some slack.
