Confession time:
Maybe three years ago, due to..um..various distractions, and a liberal measure of stupidity, my car was towed in gear, with the plugs out, for about 4 blocks, with the oil below the pickup.
Not as bad as the above, but pretty bad.
There was some signs of white metal in the sump, presumably from bearing surfaces. I doubt this metal itself is very damaging (since its soft) but of course its a symptom of damage.
Its still going. It perhaps helps that I have always used 40W oil (or 15/40) rather than the 10-30 recommended or any of the skinnier modern brews.
Why the recommendation above for "Mobil 1 or any good synthetic?". What difference is that going to make, apart from adding expense to what may be a lost cause?