I know we’ve all said this before, but if Dorothy hadn’t surfaced, can you imagine how much MORE clueless we would be than we already are?? (I believe they did not mean for her to rise to the surface, but they underestimated the amount of weights necessary to hold her down). It reminds me quite a bit of the Delphi case - in which we have the video footage shot by the victim, almost certainly unintended by the killer, yet it seems to have brought is no closer to solving it.
But what Dorothy being dumped so far into the lake does tell us no matter how we slice it - the offender used a boat. And that means he owned one or rented one. That limits the pool of suspects to people on the lake with boats, or rental outfitter clients.... unless he trailered it to the lake that day which would very likely result in witnesses.