I think your quarrel with RD is based on that you haven't followed what he has written in the past; The appraisal firm used a PE of 10-12 and ended up with the value RD is referring to.
The interesting argument here would be what PE TRW deserves upon listing on HKSE (or whereever it ends up), i.e whether the PE of 10-12 is fair or not (although it should be conservative).
Another interesting question is how much TRW will grow until listing.
For his statement to add TRWs profits since the appraisal value from 2016 this is wrong if TRW is unable to use those profits to generate more profits, they are right if they have been used to generate more profits of the same PE (10-12 in this case), and they are conservative if they are able to ramp up faster with these profits than what they have proven in the past. However, I believe this uncertainty drowns in other uncertainties (like the issues they have with AF4)