One thing I'm a little puzzled over is the fact that the crash site was near Bochum Woods (Stadtvald?) yet it says he is on the Runnymede Memorial. I have asked elsewhere and whilst there appear to be no local records as to any burial, it might be that his body was repatriated to Greece after the War by his family or the Greek government
I'm afraid it more likely that there was not enough of the body found after the crash to bury. For the remains to be classed as a body and buried, IIRC and not to put too finer a point on it they needed to find enough identifiable remains to be buried. If not enough identifiable remains were found then he would be commemorated on the Runnymede Memorial.I have it in mind from somewhere that this was considered to be about 1lb or enough to fill a 1lb jam jar.
As an example, my great uncle's Halifax crash landed and exploded just after take off from RAF Melbourne (10 Sqn). Of the 7 crew, 1 survived, 4 are buried in various cemeteries and 2 are on the Runnymede Memorial.