[Al Skierkiewicz]

Chris,
Sorry, I don't use Labview and I don't have access to it at work or at home. The waveform for the Victor looks as I would guess with no discharge path but the Jaguar shows some discharge path with the obvious triangular waveform expected for a closed circuit. We know that the EMF does not approach battery voltage until the motor is at free speed so at 30% duty cycle even with no load, the EMF is much lower than the battery. I agree the diodes conduct during the immediate discharge voltage spike following turn off, but rapidly falls to EMF-motor resistance voltage drop, which is still much less than the battery voltage. Since the battery is on the cathode of the diode/FET string and the lower EMF is on the anode, the diodes do not conduct during much of the off period.
However, just to run a simple check calculation for current in the Victor during turn on, the motor current works out to over one hundred amps at 30% duty cycle. Even if I work in some numbers for the series resistance (battery internal resistance 11 mohm, Tdson of all FETs=5.3 mohm, motor resistance 90 mohm and allowing for 10 mohm of wiring losses that comes to 116 mohm) the motor current still works out to 95 amps at 30% for 120Hz and a little under 2 amps for the on period of the Jaguar at 15kHz with the same duty cycle.