That phrase "about the best answer he can give" begs the question. Is it the best answer ANYONE can give. I'd say, No, it's not, because what he's saying is open to interpretation as amounting to wanting to ensure the OSC restricts its work to Russian interference in the election process WHILE excluding pursuit of Trump. Many of us believe that based on all that's been made public to date, those two goals head towards the same end and that proposing to bring closure to either means pursuing closure to both.
One reason we have for taking this more cynical view of what's being put out to the public in advance of Barr's appearance before the SJC is that memo he sent to the White House and DAG Rosenstein's office. The contents of the memo are contentious, though not in ways that many suppose, because following it closely would actually allow for indicting a sitting president, at least in relation to several categories of obstruction. Still, in addition to there being some parts to it that are open to being criticized as actual mis-characterization of the state of the law, the fact remains that it's tone, it's emphasis, it's comment about "balance" and indeed the very fact of it being sent must give rise to serious concerns.