Flying sparrow hack in arena?

[dklm]

I was fighting a blade dancer and in combat without windwalking he does flying sparrow and stuns me from behind.  How do blade dancers do this?

 

Edit: Actually maybe he just did a quick lightning draw and RMB stun, not sure.

[Asuramon]

If they were in draw stance after the stun then it wasn't flying sparrow.

[FrozenB]

It is RMB stun from drawing stance. The animation does look like flying sparrow.