Yes, you will not get blur shots unless there are too much light reflecting on their face. The flash already freeze the moment for you.
http://www.youtube.com/watch?v=n6Er4W-gfwU
After watching what Chase does, it's actually the same thing after all.

I open my shutter to 2sec @F13. After opening the shutter, I trigger the flash together when Eric cut the bolloon.
