As long as he uses “magic” words/phrases such as “to the best of my recollection”, “I don’t recall”, “if my memory is correct”, “I’m gong to have to check my records”, etc., he’ll be OK.
Mueller would love to trick Bannon into a faulty memory “perjury trap”.
I’m sure Bannon’s IQ exceeds Mike Flynn’s IQ by at least 40 points, so I don’t think Bannon is going to fall for any nonsense here.