I just finished the entire podcast. I was a student at SJU at the time and actually drove into campus around midnight The night Josh went missing. I tried to recall everything/anything about that night, but everything seemed normal.
The podcast did not consider, when discussing drowning, that (this is sort of a memory of a memory at this point) there was a thin layer of ice that night. Additionally, the shortest route from Metten to Maur is over Stumpf Lake. My suspicion at the time was he was drunk, decided to take a short-cut, and fell through the ice. By the time anyone noticed he was gone, the ice had melted.
While I’m not saying he drowned, that seems unlikely to me now, if he were to have drowned, it is is much more likely to me that the scenario I mentioned is what happened, as opposed to him entering the water near the road/bridge as the podcast had discussed.