I think that it is highly unlikely you destroyed the engine. From what you describe, if that were my car, I'd replace the oil pan, fill up with Mobil-1 15W-50 synthetic oil, & drive it. I bet there are no ill effects. Now if you ran out of oil on the freeway, at high RPM for 30+ seconds, yeah that could be bad. But low RPM, low load for 20 seconds really shouldn't have created a paperweight. Keep us posted on what you find out. And remember that a rebuilt OM602 engine will be in the $5-$8k range - plus labor to install!
