It is not a crime to lie to reporters but it sure is a crime to repeat that lie to the FBI and GJ.
Well it depends on how they asked the questions.
Not is you state "I told the reporter "X" which is a lie.....Those with selective hearing may have missed the last four words.
I know what you mean, but that's not said quite right. He can repeat the lie to the FBI and the GJ, he just can't present it as a summary of what happened. It is, however, up to the prosecutor to ask the question clarifying the difference. If he says to the GJ that he told reporters that Russert told him about Plame, then that is not a lie if Russert didn't tell him about Plame. It is only a lie if he didn't tell the reporters that - though that can be pretty hard to prove.
I know from experiments that many many people don't hear what is actually said. The source of "other reporters" is utterly unimportant and not likely to be recalled by people digging for information from Libby. We have accounts of how mangled Miller's notes are compared to what happened in meetings.