"the paper's editors are splashing Rove's own lack of detailed explanation detailing his press contacts."
Because that would be a violation of the grand jury secrecy laws.
WItnesses are not bound by grand jury secrecy laws. Only the prosecutors are.
If you are called to testify before a grand jury, there is no law that would stop you from finishing your testimony, walking outside the grand jury room and holding a press conference disclosing every word of your testimony.