Well, when someone says "A, definitely A" in their testimony, and then says "well, actually it was B" on cross-examination, with A and B being completely contradictory, that fits a reasonable man's definition of perjury.
It would if the first statement was intentionally false swearing; not if it was inadvertent error. Self-correction is permitted before the matter becomes a crime.
Which side did you have in mind? Michael has made numerous contradictory statements under oath. I don't recall Judge Greer recoiling from those lies.