It was Steven Gerrard.
Doesn't involve any opinions on a penalty, or did the player really commit a handball in the box.
It's did the ball cross the line and requires only a goal/no-goal comment down to the match ref
I could be wrong, but I don't think it was originally given by the ref or AR, but the ref's watch buzzed so he awarded the goal.
That is goal-line tech, not VAR. The referee gets an indicator on his watch if the ball crosses over the goal line completely.
I'm not sure if the goal-line tech is directly related to the replay that shows the distance on the TV, but I assume it's the same camera system. So 1.2cm was probably pretty accurate. Doesn't look like it could have been any closer.
VAR is simply the use of a dude that looks at the technology that already exists in these matches and then makes a call based on what he sees.
Essentially it's the equivalent of the challenge booth.
So when you see the technology and the broadcast display "goal" or "no goal" that's taking some liberties with the broadcast. Like in baseball when they show the K zone and say whether it's a strike or not. At the end of the day, the refs get to do whatever the heck they want.
The goal line tech covers if the ball crosses the line only. If it does, the ref gets buzzed. It is not VAR in that it is real time and is only for the goal line. It has been used for 4 or 5 years in the BPL.