Stig,
There can be a large volume of confusion associated with this kind of research, and the fact that something is published is unfortunately no guarantee of the factual nature of what is on the page. All kinds of factors can lead to incomplete, misleading or erroneous information ending up in the public domain, even with the best and most open of intentions, and certainly transcripts of original documents, or even the original documents themselves, can contains errors.
On the two crashes that I've been researching (PL896 and FW211), I can point you to both online and offline sources which are either dubious or just plain wrong. According to his book 'One Flight Too Many' for example (a cracking read, by the way), Jimmy Taylor has the date of John Brodby's death wrong, and he also appears to have taken at face value an online reference to Brodby's crash having killed three civilians. This reference has since (and with a fair amount of heavy lifting) been rescinded by its author due to lack of evidence, and now seems to be a conflation between this crash and that of FW211 nearby, in which several civilians died. More information about FW211 and its upcoming memorial ceremony here…
http://hewasahero.wordpress.com/
The 16 Sqdn ORBs don't seem to say how John Brodby travelled to RAF Northolt however, and nothing rules out him having flown a different plane in each direction.
If we both keep worrying away at this, maybe we can get to the bottom of it. Are you up for it? I am.
If there are other documents at the National Archives, IWM London or the RAF Museum London you can point me to that promise to be relevant, I'd be happy to go and have a look.
All the best,
hewasahero