DRV11873: What is meant in datasheet by "high speed" application?

Part Number:DRV11873

In section 9.2.2 of the TI DRV11873 datasheet is states:

– If the motor is high current / high speed, use three Schottky diodes between the phases and ground.

What is high current?  

What is high speed?

I ran chip at 14V to drive a 3 phase motor with speed constant of about 1000 RPM/V without the above mentioned Schottky diodes.  Motor was drawing < 0.6A.  

IC failed.   PWM input is now pulled to +5V always by the DRV11873 IC.  Did failure to use the three Schottky diodes cause this? 

Thanks,

Dave