Lauda will sometimes remove negative ratings that result in the other person stopping being critical of him. It is not always people that can affect his trust score, however it is probably people that are making good points. It is fairly clearly a quid pro quo.
Why is this a problem?
Seems to me that Lauda is a good trader. He must do well in bitcoin.
Personally, I don't care how others trust me when I am calculating my trust towards them. I've removed someone's negative trust while they have negative trust against me. If they remove their trust later, I don't know, because I don't keep track. Blackmailing me with negative trust leads nowhere.