Uh, no, I don't think that's it (the crash - they identified someone else as responsible for that)-- Sean had stolen the case of poisoned wine that was missing and sold it to a wine dealer. The people who bought the wine from that store (at least the couple at dinner) died.

While Sean didn't know the wine was poisoned, his actions resulted in the death of those (and maybe other - I sort of lost track) people. He was the one the owner mentioned who came back and bought back the remaining bottles from the store keeper.

He will almost certainly be charged - possibly with felony murder (not sure of required elements) but at a minimum with manslaughter. He had to be arrested, but they're unlikely to throw the book at him.