Hello,
I have also stalled the vehicle when snatching another vehcile on soft sand. I had numerous attempts as the vehicle I was recovering was immobolised and unable to assist. On the attempt where the vehcile stalled I had a decent amount of revs on board but as soon as i realised we were no longer going anywhre I released the throttle suddenly to prevent digging myself in. I had noticed during this recovery that when I backed off the throttle that the TC seems to apply the brakes to scrub off the momentum in the drive train which is very handy as that is exactly what I was trying to achieve.
I put the stalling down to the torque converter either being locked by the ECU or at sufficently higher enough revs to be locked and then the TC reacting so quickly that it actually locked up all wheels before the ECU realises it needs to unlock the converter or the revs drop sufficently to become unlocked hence stalled engine. I am sure there are some transmission gurus that know more about this than me and hence whether this theory is sound.
Did not seem to have any adverse effect so I just restarted, thought it was interesting is stalled an auto, and continued to assist the Toyota:).
