>because the space suits were bright white, the earth was bright in the sky, and the LM was fairly reflective....<
Yes... if you look at a number of photos, you can see that there is a lot of bouncing light, due to there being no atmosphere to hinder it.
However, the particular linked photo stood out.
The LM is away to the top right (so not affecting the shot), and the sun is definitely behind the astronaut..... in this case, it's hard to see how the space suit is having an effect in this situation.
... and if it was (say off the shoulders) it would be directing light outwards from the center, pushing the shadows outwards (right & left).
I do note that somebody agrees with the wide angle lens suggestion..... but if we take this to the extreme, and consider a fisheye lens: everything to the left and right of centre would be pointing outwards.
... at least I think I'm right about that.
I'm an ameteur photographer, and like you, have heard about these odd shadows.
I was so pleased to be able to find such a good example to post here.
Maybe there is an El Reg pro-photo contributor reading this thread, that can clear this one up?