Lum's Mini Rook Item did no damage

I used item toss as Lum against Geiger on Grave’s snow stage. I got a Mini Rook. Geiger had one lifebar left. I then got a fireworks item, which Geiger took two chip from. He was stuck in corner, and the mini-Rook walked up to him so I expected him to be dead from chip damage.

Instead of dying to chip, it looked like he got hit by the mini-Rook (even though I think he was blocking?), but did not lose any life. He then kept playing and trying to attack me, and actually got hit by the mini-Rook twice more without dying despite being on one life bar.

I killed him with a different attack

This was an online match


Mini Rook only deals damage the first time it hits. I think it’s meant to be this way.

Oh? Well if it’s a known thing that it only deals damage first time it hits, then that would probably explain what happened

But has this actually been confirmed as intentional somewhere? Was it reported? Because it seems… extremely counter intuitive that its second and third hits would do no damage