FOC is unstable with large Outrunner and had a hardware failure.

I have a  new 100/250 driving a  FreeRCHobby 120-100 (12kW rated) which is driving a Rotrex supercharger.   I need about 9kW at 6krpm (14 poles) which is about 65V and 150amps with this motor.  I ran the FOC setup for a large outrunner.  It worked fine with the motor unloaded, but when I hooked up the supercharger, it tripped out at around 4000 RPM due to an absolute over current error.  I lowered the absolute current to 250 amps while I debugged the problem.  FOC Setup had it at around 420.  It turns out the PID loop appears to goes unstable over 4000 rpm, with the motor current oscillating from 50 to 250 amps, with an occasional higher peak.  I was able to tame it down somewhat by increasing the switching frequency to 50kHz and lowering the gain.  At about 50 amps pk-pk I thought it was useable, but not ideal.  I then tried BLDC mode which, after a clunky startup, ran great.  I had 6krpm at around 150 Amps, about as expecting.  I thought I was done until I looked at the  sampled data and saw what looks like a dead high side switch on one phase.   I was amazed it was running as well as it was, but the current on 1 phase never gets above 0.  

I have a youtube channel which shows my setup and early testing.

I'd like to run FOC, but I'm ok with BLDC.  My speed controller is probably damaged.  Suggestions?

Steve