In the pilot (or within the first few episodes), James mentions that Laura mentioned to him that Bobby killed someone.

Most people also forget that Bobby murdered somebody and nothing really came of it. He never faced any consequences and it didn't affect him emotionally. It kind of just got dropped.

I think the largely negative response a lot of people are having to this episode comes down to the studio audience. They were church quiet at stuff they'd normally howl at. That kind of silence gives some people cognitive dissonance.