The claims are that they made public comments denying that the death was due to pertussis, despite there being no medical evidence to support that. Admittedly, these are supposed to be on blogs and Facebook, and I haven't yet seen hard links (or screenshots), so who knows. There's some implication that they've received harassing emails too.

Anyway, the family involved have made a formal complaint to the HCCC, who I'm sure will do a more thorough investigation.