Liverpool wasn't bad in this game, but Arsenal played much better, that's what I saw. It's true if you remember what happened to Manchester United last season and then Liverpool this season. They are far from what is expected, the presence of Nunez who is widely believed to be able to add to the attacking power in Liverpool's front line so far has not shown anything special. Indeed he scored in this match, but that is not enough to say that he played well. On the other hand, we can't blame Nunez for his unpredictable play because he also doesn't get a good supply of balls from midfield.
Arsenal were creating lot of chances and it was obvious that they will get the third one as well and they find it through penalty created after lot of press and shots. Nunez needs time to adjust and develop. Maybe Liverpool went a bit ahead with his transfer but I think he is a great talent. Yes, lack from supply from midfield is also a point but I still think he needs a bit of more PL experience and adjust into style in which Liverpool plays.