Where do you think BK and the DD driver could have mutually stopped? IIRC Gray Hughes mentioned BK possibly pausing on the side of Taylor Ave (the road just down the hill from the house, parallel to Queen Rd and leading to King), but two strangers are unlikely to park abreast one another on the side of a road.
Also, even if BK and the DD driver did somehow end up parked, however briefly, side by side, how would she have seen into his car? Her face may have been illuminated by her phone as she tried to figure out where on earth 1122 King Road was (well, on Queen Road, of course!), his phone was turned off. Nothing illuminated the interior of his car, except perhaps a street light. But the night-time body cam footage of the house showed that it was exceedingly dark in the front parking area, even with a party going on inside.
(Pure speculation)
As many times as I've watched GH's reenactments, I remain spatially inept. Left, right, north, south, latitude, longitude, Cog A, Cog B.
Maybe the DD driver had never delivered to 1122 King before, missed a turn, ended up behind 1122 King, stopped to get her bearings, study directions, etc. Maybe she stopped on the road (Linda Lane maybe?), along the long road where BK's three point turn was captured. Maybe that's where the DD driver paused. And BK parked, there intending to army crawl the rest of the way.
Or maybe BK was in place at 3:54, parked in a primo location, all set to go in, when the DD driver approached the house. Maybe he then drove away, briefly illuminated by a streetlight, or even just ambient moonlight.
Then BK makes a short loop, returning at 4:04, craning to see if the DD driver was still there.
I think BK's movements are best explained by the presence of the DD vehicle. And hers corroborate the timing of all of it.
Master of Patience, BK waited maybe 5 or 8 minutes to park, once he determined the DD driver was cleared.
IMO BK didn't know that that encounter might later serve to convict him.
We know any transfer. Taking and leaving something in every exchange...
There's also this, similar: action and reaction. BK approached, but four times, he drove away, IMO because something at the scene wasn't as he wanted it. Too many lights, too many stragglers on foot, too many moving vehicles (including DD), BK making noise, DM hearing it. Encountering a victim, breaking his own silence. He was interacting with the environment before him. And each of those touchpoints makes for evidence.
He may have successfully pitched it, but I can pretty much guarantee that he left things behind (his DNA for one) and he took things with him, intentionally or not. Victim blood, make shift weapon perhaps, a human hair, a dog hair, something.
I'm hopeful LE discovered BK's dumping ground.
JMO