"The ref even said to H (Maguire), I heard him say 'if I say it's a penalty then it's going to cause a lot of talk about it after'," Shaw told Sky Sports News.
"So I don't know what happened there. H said that they got told it was a penalty by VAR."
Shaw later backtracked on the comments, claiming that he misheard what Attwell told Maguire, but the Daily Mail claims that the FA may still take action.
It is claimed that Shaw could be charged with the offence of "implying bias or attacking the integrity" of match officials, which can lead to a suspension.