Why does everyone seem to ignore how much Sane let us down the last time we played at Anfield?
Because they're frustrated and in need of a scapegoat?
Knowing Mahrez from his Leicester days and his penalty record, I was baffled when I saw him step up. Love the bloke but he ain't the one you'd choose to take a pen a this moment of the game, with so much at stake. Knew he'd miss it. He stopped to be the main penalty taker the last two seasons with us and Vardy was tasked to. That said, knowing his shy and introverted nature, he's certainly not the kind of guy who would take the ball of Jesus hands without being instructed to do so.
Saw your game, it was really tight but you pressed them hard and Atkinson is cvnt. It could've gone either way on a (lucky) goal but it is still no small feat to take a point from Anfield, considering Liverpool's actual form. Understand the frustration though.
As for Mahrez, he was pretty anonymous in the first half, much better in the second where he really went for it. Sure there were occasions when he was greedy but that's what you expect from a flair player. He's been certainly given a free pass in the last third to make whatever he deemed to be the right thing. For me it made sense that Guardiola let him on instead of Sterling who failed to make a decisive impact. There wasn't that much space in the final third and he was the only one to take on his direct opponent. Should never have taken the penalty though and I'm sure he'll have some sleepless nights about it.
I understand your disappointement but don't be too harsh on the guy and don't pay attention to the "body language" which I personally consider to be bullshit. He always had a laid back attitude but it certainly doesn't mean that he doesn't care. My personal take is that he has a lot to compute right now, torn between his former free-roaming Leicester way and the amount of tactical data Guardiola put in his head to adapt to a completely opposite style. That's what I saw at least. It will take some time but he will still come good, I think. Just maybe not this season though, a bit like Bernardo.
Anyway that was my 2 pennies on the matter, good luck for the rest of the season and in the CL.