I agree with you in that picture that it's hard to tell. Someone else on twitter posted that exact same situation side-by-side with a pic of a wrestling rulebook pic stating that it's illegal. I couldn't find that side-by-side pic to post. To that point, I always thought that IF the arm was trapped then it's legal. I still think all of the recent bad videos of the wrestler getting choked out might have influenced a quicker than normal whistle.To me that is a scissors but not illegal because it looks to be bastida's arm in with the head. I can't really tell on this picture.