R133 is a polyfuse, a PTC resistor that will go high resistance when it heats up enough, either from current flow through it, or from high ambient temperature. When it cools down it allows current flow again, and is probably what helped protect the rest from whatever killed those diodes and the main switcing supply.
My bet is somebody used an AC supply ( or a failed DC power pack) on the unit, and this had a high reverse voltage which blew all those parts. I would replace CP as well, it would have been damaged with the reverse voltage applied, and check D104 is not damaged either.
As to the filed via, I guess it was connected to an internal layer, and was carrying the return current path of CP, which I guess is the Panasonic cap next to it,, which would have resulted in this damage. PCB designers might have not wanted a connection to the ground plane on the top, as this can be a poor connection with the large plane removing heat, so put a small stub trace and a non soldered via as thermal isolation.