Did you watch the video?

First part has the Chainalysis agent in awe of how private Monero is. The rest of the video is him being very unconfident and admitting it was mostly guess work and probability.

Required the victim to use a malicious node controlled by Chainalysis and not using a VPN or TOR to hide their IP. Basically a network level attack. And in the end nothing was conclusive.

He still couldn't see how much Monero was being sent or who this person was sending to. If anything this highlighted the strong privacy Monero provides.

FCMP upgrade that is in the works will render even this edge case attack ineffective (assuming you are using your own node or TOR/VPN) since it gets rid of ring signatures and makes the sender a potential member of the entire chain instead of "only" having 15 decoys