Okay....after closer inspection of my bent Exotek wheels, I had found out that one of the five "reinforcing" spokes along the back had totally cracked and all the way to the front spoke.
As mentioned before, I do not recall any huge crashes or cartwheels. My Tamiya foam tire wheels have held up to much tougher abuse and still spun true. I hope Exotek adds more material to the spokes or change the material itself to something more durable.