Why does this not produce an error?

#pragma config(Sensor, in1, Right, sensorReflection)
#pragma config(Sensor, in2, Center, sensorReflection)
#pragma config(Sensor, in3, Left, sensorReflection)
#pragma config(Motor, port1, Right, tmotorVex269_HBridge, openLoop, reversed)
#pragma config(Motor, port10, Left, tmotorVex269_HBridge, openLoop)

"Right" and "Left" are defined twice. In this case "Right" happens to be 0 in both cases so it works. However, "Left" is defined as 2 for the sensor but then redefined later as 9 by the motor definition. The "Left" sensor does not work in the code because it points to the wrong port.