Bunch's point was to say that through the affidavit submitted by Houze to Kaine's attorney that the money paid to him came directly to him from a third party and was never in Terri's control, therefore was not marital asset or property, nor was it a gift.
Under any one of those circumstances, let alone all three, Kaine is not owed an explanation as to where the funds came from. Bunch further states that, because it's not marital asset or property and was never in Terri's control, it will also not be relevant when they do divide property, because at the time Terri attained her defense attorney, Kaine had already filed for divorce, rendering them legally separated and making null his right to know for marital asset/property rules.
Saying "why doesn't she just tell Kaine where she got the money?" is ignoring the point that the money went to Houze, NOT Terri at all.