Please don't think I'm crazy, but were you wearing boots?

I find the distance between the accelerator and brake pedal in my 300SDL is a bit narrow. My size 12+ foot will sometimes bridge the gap, so that I'm applying accelerator when I'm braking unless I concentrate and move my foot more positively towards the middle of the brake pedal.

If you were wearing boots, which are wider and give you less 'feel' from you r feet, it is possible that when put your boot on the brake to shift from P, the edge of your boot pressed the accelerator.

If that happened, and you were not aware of it, the car is going to do weird stuff, like accelerate harder as you press the brake. The result could, indeed, be your smoky burnout until you put the car back in to P!

This same unintentional brake/accelerator pedal activation was found to be the most likely cause of the infamous Audi 'runaway' engines, since they never found any demons...

Best Regards,
Jim