Just speculation....
Had a feeling when Lauren left CR's and MB's townhouse, she intended to go to JR's. I would guess that was a half hour or less after arriving at 5 North. After she leaves their townhouse, having to go outside to enter JR's place, she was either unsure of where she really wanted to go (JR's home? JW's), or confused, or some kind of drug had really kicked in. It might've been 3:58 AM (instead of 3:38) or whatever, but I do believe she was seen in the street, pretty much passed out, or on a step of a breezeway.
I think the guy who offered her help took her back to JR's and left. That seems to be before 4:15 AM when JR's phone made the call to DR (had to be an emergency call, unless it was to try to get downers for JR to get some sleep IF he'd been doing coke or other stimulants all night). I guess there's a slight chance Lauren called him, but if the (supposedly 3:38) witness report was correct, Lauren was not in any shape to make a call. So JR was left with the nightmare of a dangerously ill girl being delivered back to him, and then.... well, it probably just got worse...