I didn't say all were now did I? But those 'eyewitnesses' (so the people he flew with) are going to be at the very least his comrades. Of course the British are going to be biased, so are the Germans though.
& 3 down of British/allied side, Taffy, Winters, & Bickers. Which leads us back to the original point of Richthofen lurking above seeking novices. Which has no credible data to authenticate it. I found this in Richthofen's Air Combat Operations Manual. "Whoever is first in position against the enemy has the right to fire. The entire Staffel goes down with him. A so-called 'cover' at a higher altitude is a cover for cowardice."