Lebron had 35 points, and 10 points in the fourth quarter, so I'm not going to sell him too short. That's a pretty good performance, by any stretch of the imagination.
As for in general, the past two seasons, Lebron has been amazingly clutch. He carried his team to the Finals last year, and this year he led the league in fourth quarter scoring (and was third in fourth quarter assists), and also led in scoring in "clutch" and "super clutch" situations as defined by 82games.com. The only player to even come close to him in all-around game in tight situations was Manu Ginobli.
I understand that a lot of people don't like Lebron, but he's been coming up huge for the Cavs all year long. To fault him for one less than stellar quarter seems a little over the top.
(It's pretty clear his shot hasn't been falling this series, mostly due to our defense but also due in part to a slump on Lebron's part. However, he's still finding ways to contribute, mostly by getting to the line, and setting up his teammates for easy looks. That's what great players do when they're struggling.)