Incoming speculation from me.

THAT could certainly explain alot. And it makes a lot of sense to me. The idea that a second non-resident male ran into the house, killed everyone, then naked from the house while BK was circling the neighborhood in his car is just absurd to me. I
suppose it could be argued that a second person entered the house either naked, or stripped off before leaving. Of course, then I have other questions, including 1) how did this person get to the house? 2) were any other cars seen on video circling the neighborhood during that same period of time?
It could also explain the THUD (throwing the bloodied clothes into the trunk) and him driving quickly from the area. And the long drive. Because somewhere he would have to stop and dress without being seen.
Assuming the Mirror is not publishing total fiction today, and BF did see a naked person after DM saw a person in black, I can totally see the defense trying to interpret that into something besides BK stripping off bloodied clothes at the door on his way out. I don't think it will work, but it's a logical thing to try for.