Regarding the Mal-Val narrative, absence of evidence doesn't by itself provide evidence that the Mal-Val narrative is invalid, only that it is not supported by evidence.
Regarding the BHO Sr.-SADO narrative, there is substantial contemporaneous cross-corroborating evidence which supports SADO as Barry's mom and BHO Sr. as the most likely sperm donor, but I have seen no evidence establishing conclusively where SADO was when she gave birth. I have seen a lot of claims that cross-corroborate that SADO was most likely in Kenya when she gave birth.
Absence of evidence in the nature of lack of baby pictures prior to the zoo picture taken with the mom (which I regard as genuine) or grandparents does not prove that such pictures were never taken and is not evidence of absence (evidence of nonexistence) of such pictures.