If SPLC is responsible for the shooting because they labeled FRC a "hate group"...

...then what responsibility does FRC have for actually being a hate-filled group?

Isn't it a bit like complaining, "Joe punched me because you told him I slept with his wife."

But you did sleep with his wife.

That doesn't mean he should resort to violence, ever.  But you did sleep with his wife.  So let's stop pretending that the sinner here is the guy who caught you.