What do think?
From ~ Alfred Lambremont Webre NZ Astronomer debunks M. Masters: There is no brown dwarf star ("Planet X") in our solar system
David Greg has provided a written summary of his analysis in the ExopoliticsTV interview as follows, with article and references here:
EXOPOLITICS: Politics, Government, and Law in the Universe: NZ Astronomer debunks Marshall Masters: There is no brown dwarf star (?Planet X?) in our solar system