It was a weird one - as Bjornar says, Sean Rogers said Henderson ploughed in to show Keita how it was done... I'm not sure he was saying Henderson was doing what he was supposed to though. He did desert his own station. I think he was just rationalising what both players did in the situation. He did the same re Fabinho's reaction too a moment later.
Again, I didn’t hear it so I should be careful. But there’s no question that Keita triggered the press by a smart and really intelligent move beyond McArthur’s blind side. I’m sure he was hoping that McArthur would turn that way, straight into his path. He didn’t of course, but the other lads were now smothering him on the side he could see, and they’d reacted just as Klopp wanted them to react as soon as they saw Keita make the trigger run.
Fair play to McArthur, he didn’t panic and somehow got the ball free from Firmino. At that point Liverpool, as a team, needed to reassess because McArthur was facing the right way, with the ball at his feet and ten or so yards of empty space in front of him. That is emphatically NOT the time to press. You can see Robertson understands this because he checks his forward run and tucks in. Henderson however went on a mental one, storming past one Palace central midfielder (so putting another opponent in lots of space in a by now rapidly emptying midfield), and storming straight on to McArthur. It was the easiest thing in the world for the lad with the ball to dip a shoulder and evade Henderson’s charge.
I’m afraid that is about Henderson NOT understanding the press. It’s not the first time I’ve criticised Hendo’s tackling technique, which can almost reach Jon Flanagan levels of innocence on occasions. You can be the swiftest player on the pitch but if you charge at a professional footballer who is facing towards the goal with the ball at his feet he’s going to dribble past you and say ‘ta very much’. That’s what happened.
Keita, on the other hand, showed he is getting it - something confirmed by the stats you posted earlier.