Actually no. It's confidential to the grand jury and will be sealed unless there is an indictment handed down. (I spent 3 years on a federal grand jury and heard this adminishment on a daily basis!)
But I believe the person testifying is free to go out and spew? At least I can recall hearing that. But the person is under no obligation to be honest about what he tells the public. So he can lie to the public all he wants as long as he doesn't get caught doing it in front of the gj.