Board Thread:Naruto Discussions/@comment-4271790-20141008103341/@comment-17623-20141008185928

To avoid the wild mass speculation thing, I'm guessing it was artistic licencing Questionaredude.

He launched 3 to block Sasuke's attack, then had to resort to Tailed Beast Mode tails to block the next. By making him spend his Truth-Seeking Balls quickly, it got him to transform so we could have the giant bro-fist moment and they don't have to drag that crap out.