I don't think it's a penalty by rule. However, (as noda suggested) if you make everything reviewable including penalties I bet that call on Matthews does not get overturned. The league is emphasizing it so much, they don't change the call. Really wish I didn't love Packer football as much as I do, because I hate so many things about the NFL rules these days. I mean look at what we're doing, most of the conversation is about the refs- and didn't even mention the phantom holding penalty, ticky tack call on Adams, ripping Grahams arm down before the ball was there, etc. All the illegal contact, holding, etc. is always so wildly inconsistent.