Is that supposed to happen?

I was playing a game to test out jungle Yi, and discovered that his double strike will trigger itself.

Below is a chart of what his passive is doing if he stays in combat. The I marks are regular attacks, the X marks are when he double strikes. I, I, I, X, I, I, X, I, I, X, I, I, X, I, I, X, I, I, X, I = (20 standard attacks, 6 double strikes)

Now, a chart on what should be happening, if I read his ability right. I, I, I, X, I, I, I, X, I, I, I, X, I, I, I, X, I, I, I, X = (20 standard attacks, 5 double strikes.)

Thankfully, sated devourer isn't ALSO triggering his passive. Otherwise... I, I, X, I, X, I, X, I, X, I, X, I, X, I, X, I, X, I, X, I = (20 standard attacks, 9 double strikes.)

Like I said, I don't know if this is a bug or not, but it makes his jungle clear times a little bit faster than they maybe should be, and means that he can keep a monster stunned for most of his time in it's camp, with the Krug buff. With Sated kicking off... well, let's just say it's a good thing the dragon and baron are immune to stun.