Just renoting possibility mentioned at some point upthread that JD (and/or an accomplice/s) may have been transported or transporting somewhere while alive but in one or more ways silenced, contained, or immobilized. Dupe accomplice may have been hired to relo a box or container of "household goods" to different location, perhaps storage unit, random isolated place, or somewhere where transport person was for whatever motive/need terminated -- perhaps questions or suspicions were raised (such as the person thought s/he heard movement or because it'd always been the plan to disappear that person and frame the dude for the crime), so having to suddenly dispose of two bodies rather than one became a complicating factor.
Again I recall the case from the early 1990s were an Exxon executive in Florham Park, NJ was injured when placed into a storage container then placed into a storage unit, not provided with medical care or hydration, and later died of his situation and later was moved from the storage unit out of state and buried deep in the NJ Pine Barrons (sp) national forest.
FD may have thought he'd killed JD before putting her in the container, leaving open the garage door, and the container there for the dupe to pickup and relo, so assumed he'd have time to dash back and clean up or have MT or a third person do so, or didn't expect to even make a mess but JD fought back more than anticipated. Having to clean up two crime scenes and dispose of two bodies would complicate things, as maybe this had not been build into the plan, especially as/if FD had planned to keep MT in the dark on a lot of it or feed her false details so as to later be able to frame MT for any loose ends or the plot, were this to become necessary.
So if there's a body in the pond, it may or may not be the moving man. If JD was still alive during transport, this could have impaired ability of K9s to detect cadaver scents, or different vehicle/s were used and then also dumped (such as moving man's truck).
Also possible, a Land Shark scenario. Some one spoof called or messaged JD on the morning she went missing (falsely) notifying her of cancellation or rescheduling of her 11 a.m. in NYC, or some fake alert or call about the children, then a delivery person showed up at the house, or someone there with a forged order to seize or deliver certain personal property items or household goods. Anything to throw her off guard. Either she fell for it, or when paused to question this or immediately sensed danger, she was quickly incapacitated and a clean up man brought in. Stun gun maybe. Injection. gagged, ziptied, duct tape. Or chloroform. For sure there was JD's blood. What we don't know publicly is when, how much, and whether from inflicted or defensive wounds.
All just left field theories. Still think for sure that a body of water somewhere will play a role in this all, as will one or more patsies, ideally to FD shady and undocumented, any criminal history of said person/s all the better. Just guessing. Pure speculation. No proof. MOO.