Maybe they just forgot to indicate it and can't quite remember during the post analysis which one they moved?
I guess its possible that they didn't realize that another piece could have moved there, which may indicate that they aren't seeing the whole board. But, with new players, I think just going through a game and seeing the blatant mistakes (like hanging a piece) and all would be a better indication.
A lot of new players write say,"Rd1" and you ask them "which rook?" and they give you that horrified look of ignorance. I'm wondering if neglecting to specify which rook or knight is an indication of the player not seeing the whole board including all the pieces.