" ... the alternative scenario-DW and Brenda VanDam know each other a little better than has been admitted to,and the DNA is indeed VanDam DNA,but it's Brenda's,not Danille's,and that the testimony has been cooked just enough to obscure that fact."
The only way I think it could work is if they did mDNA testing on the jacket, rather than PCR-NDNA (nuclear) tests.
That would be a flat out lie under oath by the SDPD Tech and Dr. Holland of Bode Labs.
William of Oakham sez: Detective Ott "salts" his evidence.