Good Catch Skylogger Larry!
That is a very important circuit, and that resistor is too. i think i made a post several pages ago about those two big chips that are jumping across the isolation slot cut in the circuit board, PC312 and 313, which are Broadcom A782T isolation amplifiers [with fixed gain of ~8x] used to measure the OBC output voltage and current. These feed into the small IC501 2746Z op amp which sends the signal back up the CN1 cable to the top board.
The output current is read across R232 which is near the base of the output filter cap, C115. The board looked scorched to me in one of your photos, the resistor is probably okay.
The OBC High Voltage output is divided down on the bottom side of the bottom board thru a series of 330k resistors, R431,432,433, this is then fed thru another voltage divider on the topside of 1k and 560R into the PC312 differential isolation amplifier. The differential amp will reject common mode noise on the buss line and provide a clean signal representing the voltage of the output, or across the current sense resistor in the case of PC313. The differential output of the isolation amp is fed into a non-inverting differential input-to-single output stage with a 39/20 = 1.95 gain from the IC501 op amp.
Using 360VDC as the charger HV output, the input to pin 2 of the isolation amp will be about 200 mV, and with a gain of 8 the output will be 1.6V. This is then fed into the 2746Z op amp and results in ~ 3.12V signal that is sent over the CN1 pin 42, likely as input to the microcontroller, but i haven't traced that far yet.
With the twisted sister resistor going open circuit, then the op amp becomes a non-inverting follower with a gain of 1+(39/20) = 2.95, and now the output goes to ~4.72V, nearly to the 5V rail. The diode circuit on the ouput would clip that back down a bit, but the microcontroller would be seeing an abnormally high voltage reading. We don't know what it would do in response, but most likely shut down the FETs in an attempt to lower the HV. It may be a sudden shutdown could cause the snubber capacitors in the potted doghouse to see a massive overvoltage and this may have caused them to blow.
Here is the current sensing circuit also, which uses the other isolation amplifier that bridges across the gap in the pc board. When the OBC is on but no current flowing, then the CN1 pin 41 voltage will be about 0.65V. When the current is 9 Amps, then the top board will see 3.3V. At higher currents the voltage goes up until it will be clipped, but the microcontroller will likely take action above 9A to limit it, since that is pushing the limits of what can be done with a 3.3kW charger (360V x 9A).