I think from that angle it doesn't look good. The other side shows his hand getting him high on the chest, maybe neck, but it doesn't impact the nose.
m8. I will fight you.
He swings his arm around in a successful attempt to wrap the ball. On the way through he catches Jones' nose. I don't think anyone is saying it was malicious, but it was a swinging arm in a tackle that resulted in an injury. If it happened in open play a ref would normally have a second look at it.
But then defenders are given huge leeway to do all kinds of illegal shit when they're attempting to save tries. And, as I mentioned above, Walsh was taking a very casual attitude towards high shots all game so it shouldn't be too surprising that he let it go.