Sensing BLDC motor torque using a current sensor
It depends on the motor driver, but in the general case you can't expect the driver input current to equal the motor current.  This is because good motor drivers are essentially switching power supplies, using the inductance of the motor as a integral part of the supply.  The current thru a winding can be higher than the supply current, just like the output current of a buck switcher can be higher than the input current.