Now here is a thought and this is based on looking at the maps and satellite images of the area of the incident.
We all know that the LoAC is not a hard and fast line but more of a fluid zone that get fixed by hard points, established by the sides coming up against each other and pushing.
It is easy to see why the knee of land by that bend in the river would be attractive to the Chinese commanders and why they would order their units to secure it as a hard point.
India no doubt would also feel the same and realise just how great would be the disadvantage to them if the Chinese were to take control and fortify it.
Now, just look at the map and pictures and ask yourself this.
How exactly do the Indians cross over to the Chinese side to try and conduct an operation?
Only two ways I can see
1) Cross the River
2) Mountaineer across the mountainside/valley wall
Both of course at night in the dark.
So, we know it was an attack from the Indian forces, both Modi and Chinese Foreign Ministry agree that Indian forces crossed into Chinese held territory and that no Chinese entered Indian held territory. Remember also that "Attack" is a mission catagory and that it is clear that the Indian forces intended to take and secure the knee of land within the river bend. Even if not a single blow was landed, it would still be catagorised as an attack.
We also know the result. Twenty Indians,including senior officers dead, nearly eighty injured and at least ten taken prisoner, with minimal or no casualties on the Chinese side. Other than in a Kung Fu movie, what set of events could realistically produce this sort of outcome.
1) Chinese forces knew that the Indians commando style raid was coming and sprang a perfect ambush on them. Possible but still sounds like Hollywood.
2) The River crossing was a disaster. Yeah - to me this seems far more likely, that something went wrong in the river which resulted in dozens of men ending up in the water. These rivers are dangerous, distant rains can send instant torrents downstream and distant rockfalls can send tidal waves a long way as well. Even the chance of substandard boats/dingys for the night crossing.
If the falling down a cliff part has merit, than maybe it was a climb across the steep valley wall to reach the Chinese positions and they all came down into the water as they approached - assume they would all have been tied together at that point.
Either way, to way it does make a lot more sense of what we know.
To be honest, I would really put my money on something like 2, and that other than trying to effect rescue, no Chinese soldiers were involved in any combat, whatsoever.
