I think it's totally normal! You may even notice the his feet position them selves differently from one day to the next or from one walk across the room to the next. His body is just getting the hang of this kind of movement and hasn't quite figured out the best possible position.
Also, pushing behind a rolling toy can be really different than walking independantly. Think about it, every step is an effort not to fall forward as the thing you are leaning on rolls out of the way. His little feet stay slightly behind him, which would make having them point straight forward tough on anybody.
I'm sure his food position will work itself out.
T.