The collection method here do not actually verify if the information given by the DHT network is correct, which should be rather obvious when the data include invalid IP addresses. A node when receiving a GetPeer request can simply make up any claims they want.

Of course law enforcement don't operate on guaranties and even weak evidence can help if a already suspected person is involved in an investigation, but its important that we distinguish between weak evidence vs strong evidence. The GetPeer reply is about as good as an anonymous tip arriving by email.