As for the scrutiny he faced after that as compared to LeBron, well there are a couple of reasons for that.
First, whether it's right or wrong, the perception is that Kobe broke up the dynamic duo. Everyone loves Shaq. They just do. He's always been very charismatic and just seems like an awesome guy to be around. Kobe doesn't try to be like that, and when he does, it comes off as really fake. That's not anything bad, it's just the type of person he is, compared to Shaq. So when they had a falling out and Shaq was forced out of town, Kobe was blamed for it. Again, whether that is correct or not, that's the perception.
Second, Kobe had that video of him throwing Bynum under the bus. No, he didn't have many good teammates before the season they lost to Boston, but that's no excuse for appearing publicly in a video denouncing them.
LeBron, on the other hand, has a much more Shaq-like personality. Less public than Shaq, but he genuinely looks like he's just having fun out there. He seems to be more of a "fun guy" than Kobe does, and many people like him more for it. Also, LeBron's teammates have been every bit as bad as Kobe's worst, and the team he carried to the Finals was probably as bad as any team Kobe got knocked out of the first round with. But he's never publicly thrown any of his teammates under the bus and always seems to be supportive of them. So when he plays out of his mind and not one single teammate of his steps up in the ECF, he gets a pass for walking off the court like that.
The REAL question is why is Kobe so scrutinized and Dwyane Wade gets such a pass? Wade had "sex parties" for crying out loud, and allegedly gave his wife an STD. That's Tiger Woods **** right there, but he's held in the same light as LeBron still.