I missed this as I didn't watch the highlights knowing Liverpool won. But, from reading about it, it seems Friend was the onfield ref and rightly didn't award a penalty. Then VAR told him to look at it again which, as the stats mentioned show, means the ref will almost always change the decision.
So, if it's deemed it shouldn't have been a pen, the main fault seems to be with the VAR ref, Craig Pawson, for advising it? If it's 49 out of 49 times that the onfield ref has gone with the VAR recommendation, then it looks like any ref, not just Friend, would have changed their decision when advised to by Pawson.