This is a real dog's dinner. We have Hackett saying VAR should have given the penalty but he makes no mention, and probably wasn't aware at the time, of the ball touching Siva's arm first. Clattenburg says no penalty was correct but that the wrong reason has been given - Silva's handball should have been the reason, otherwise it should have been a penalty as TAA's arm wasn't in a natural position; and Halsey thought Oliver's view may have been restricted by Aguero but VAR should have advised a penalty.
Halsey's comments raised a question in my mind: we don't know what Michael Oliver saw or thought he saw and whether he had a good view (I still think it wasn't the best angle). But suppose he thought it might be a penalty but wasn't sure enough and therefore wanted VAR to look at it. Could he have blown straightaway for the VAR check to avoid the risk of a breakaway and goal at the other end, which of course is what happened? (If VAR had then stated no penalty, how would the game restart?) Or, not having made a decision, is he obliged to let play continue?
Hackett's version is wrong according to the latest version of the law on handball. Clattenburg's observation is correct but his conclusion is flawed for the reason given by Readingfan - if you allow play to continue after a "deliberate" handball then a player can catch the ball run to the edge of the penalty area and boot the ball upfield. Halsey is wrong insofar as a penalty should not have been awarded (for the same reason as Hackett) but is correct that VAR should have intervened. Play should have been allowed to continue but called back for a Liverpool free kick after the VAR check was completed. To allow the goal to stand means that advantage was given to the perpetrator of the handball, a new concept.