RateTheRef

That doesn’t prove anything!

Thank you so much for pointing that out.  It is, of course, the reason that I didn't make any claim that it did.  It does, however, let anyone who hasn't seen it have some idea of the incident that which has been referenced.  It does show that Mane's forearm makes contact with Sterling's back, we don't know, amonst other things, whether that arm is about to extend or whether it is acting a "shock absorber" before Mane runs into the back of Sterling.  But it seems plain to me that Mane is not attempting to play the ball and that the contact is a bit more than a congratulatory pat on the back for having got past him.
You on the other hand have made the assertion "Because he fell over like he’s been shot - never enough contact for a penalty!" - I await the production of any evidence to support this statement which you have presented as fact.
This is particularly the case as two of your previous assertions have been pretty much demonstrated as being inaccurate:

"if you have a look at the freeze frame as it hits Bernardo you can see TAA arm is already out poised to defend."
"What was more surprising is that aguero stops: if he did what all footballers are taught from the age of 6 which is play to the whistle he could have gathered the ball and had a shot at goal."

There now seems to be too many of these "push in the back challenges" which go unpunished. Generally the player doing the pushing has no chance of playing the ball. They are totally different to side by side shoulder challenges. What is the difference in this instance if Mane were to trip him up causing Sterling to fall over? If ajb95 had seen the incident he would have seen Sterling running at speed (and still in control of the ball) and Mane pushing him over. The still shows how far Mane is from the ball and there was a case for penalty and red card.     

How can it be a red card when it’s on the goal line parallel to the goal?? That’s not an obvious goal scoring chance.
Returning to your point microspsist, just because there is contact doesn’t make it a foul. On the handball, as i said in my 1st or 2nd post, but will repeat if unclear, I would have given a penalty but 2 reasons why I don’t think a penalty was awarded: 1. It hit bernarndo’s arm first. 2. As the ball hits Bernardo TAA is getting himself poised into a defensive position ready to deal with what aguero does. His arm has to come out to the side to give him balance and leverage - one cannot move with arms by ones side - IMO there isn’t anywhere else his arm can go in this situation. it was just unfortunate that half a second maybe less later, the ball comes into contact with his arm at that point.

Hi ajb95,
This is fun, hope you are enjoying it too.

Possible foul on Sterling - I hope I have been careful enough not to claim that this is definitely a foul, I happen to think it was but I am also aware that I don't have enough evidence to be certain.  However, the converse of that, which I was trying to demostrate is that I don't see any evidence either for such a definite statement of apparent fact as "Because he fell over like he’s been shot - never enough contact for a penalty!", even to the exc!amation mark at the end.  If you had put a question mark at the end or if you had softened it with something like "Perhaps Michael Oliver thought ....", I might not have reacted.  We are entitled to our opinions but not to state opinions as fact.

Handball.

1. It hit bernarndo’s arm first

I don't think that this relevant except that a goal should not result from the deflection, and as I said earlier I'd consider that a penalty could not be awarded for that reason.  However, that does not give the defender carte blanche to handle the ball.

You seem to have changed your position from the original post

"if you have a look at the freeze frame as it hits Bernardo you can see TAA arm is already out poised to defend."

to

2. As the ball hits Bernardo TAA is getting himself poised into a defensive position ready to deal with what aguero does. His arm has to come out to the side to give him balance and leverage - one cannot move with arms by ones side - IMO there isn’t anywhere else his arm can go in this situation. it was just unfortunate that half a second maybe less later, the ball comes into contact with his arm at that point.

I'm not sure what leverage he can obtain from an arm in mid air, however more to the point;
Elsewhere reference has been made to Aguero's arms being similarly positioned to TAA's, let's look:

In this case the centre image is the last image from the previous set with the top image being the frame before it and the bottom image being just affter the ball has struck TAA's arm.
Note that Aguero's arm is extended in the top frame and possibly in the path of the ball but in the next frame he has withdrawn it completing the withdrawl in the bottom frame.  Two points, firstly he doesn't fall over suggesting that it is possible to pull an arm in without losing balance and secondly Aguero is closer to the ball than TAA and if he has time to remove his arm so can TAA.
As an aside I note that TAA has a bit of "previous" on using his arms in games against Newcastle and Porto - perhaps he would be advised to be more careful as his luck might run out.

The Manchester Evening News uses images from a slightly different angle to make the same point about TAA's hand moving into the path of the ball. https://www.manchestereveningnews.co.uk/sport/football/football-news/var-liverpool-handball-alexander-arnold-17242608

Mention has been made of a silhouette - this seems to have been an unhelpful introduction by David Elleray who referred to a silhouette without describing what it should look like. However, I would guess that if you took the silhouette of TAA as the ball reaches his arm and told folk that this was a footballer and asked what they were doing most folk would respond that it was a goalkeeper making himself big facing a one on one.