GH and the GJ
I've served on a grand jury -- no, not THAT grand jury. I was a journalist for 30 years. And I race my bike and avidly follow the sport. So let me put this out there:
First, GJ testimony is secret under American law. Anyone breaking that secrecy, including prosecutors, the official recording secretary, grand jurors, are subject to stiff penalties, including jail time. However, a witness may tell others what he or she said before the jury and otherwise describe their experience. In reality, they rarely do so.
Second, whatever GH or anyone else told the GJ is recorded and preserved. As part of a grand jury last summer, we frequently reviewed such witness transcripts and were told each time that this was an official record. A later change in testimony by a witness, say in open court in a later trial phase, would mean perjury charges. Again, these are very serious because the whole legal system rests largely on sworn testimony.
Third, in a case with this many moving parts, it is often possible for for an experienced journalist, especially from a prestigious, powerful show like "60 Minutes," to seek and get confirmation of some sort that testimony from one witness, say TH, has been corroborated by another. In fact, it is much easier in a case like this when they already have (public) comment from a grand jury witness with which to work.
I can easily see someone from 60 Minutes approaching GH, a member of his legal team, the prosecutors, or investigators and saying... "Look, we know what TH told the grand jury" and at least coming away with an understanding that another witness had said much the same.
One can think of a lot of possible motives for someone taking that kind of risk.
Of course, we may never know what is really going on here. But I read GH's tweet and comments as what Washington likes to call "a non-denial denial." In other words, its not definitive in either direction.
We'll have to see how it plays out. If a case ever reaches open court, that is, if it's not dropped or settled by an admission of guilt as part of a plea bargain, then we will know what, if anything GH, said at the time.