This is a very dangerous statement and I completely disagree. Back in the "old days", engines did not have as high compression and tight tolerances of newer engines (especially if it were a V8). Try that with our high compression and tight tolerance engines (and with regular mineral oil) and you are asking for trouble. Yes, I have seen those commercials by Quaker State where after leaving the oil out, they run the engine for quite some time with no oil and it "seems" fine.
With our Duratecs, just having a few seconds without oil and the bearings are toast. We have had many posts on this. And this does not have to do with whether you agree to put half quart above the max line or not.
I consider it a very dangerous thing to run the engine with no oil.
That said, I'll make a few more comments.
Loosing a rod bearing on a Duratec due to low oil pressure would probably be much worse if the engine were under load. There is less likelyhood of damage with little or no load on the engine.
On the other side of the coin, I have been absolutly amazed at how much punishment some engines can take. While working in a Volvo dealership a few years back, one of the techs (actually one of the better ones) forgot to refill the engine after draining the oil. The customer had made arrangements to pick it up after hours. He had his wife drive it home while he followed in the other car. It was about 20 miles, most of it on the freeway. When they got home his wife told him "honey, there is a warning light on". He had it towed back that night and was there to meet us when the shop opened. As he watched, we removed the pan and turned the engine over to inspect the cylinders for any scoring (non found), and then pulled the bearings for inspection (all were fine). We put it back together, filled it with oil, and started it up. It ran fine. The dealership bought him an extended warranty with the understanding that should he have any lubrication related engine failure as long as the warranty was in effect, the dealership would pay the deductable. As far as I know, he had no further problems. I don't know if that was a testimony to the durability of Volvo engines, or if it was a testimony to the oil (Pennzoil).
I have also seen where for entertainment, the oil was drained from a junker car and the engine run until it stopped on it's own. Some ran for hours before they siezed up.
One shop I worked in (and I didn't like this practice, it is part of the reason that I left), when there was an engine noise complaint with an obvious rod knock, they would drain the oil and drive it hard until the rod was thrown. They believed that it was "comeback insurance" to make sure that the engine was replaced instead of just repaired. The techs held contests to see who could make an engine blow up the quickest. The shortest distance I remember was about 40 feet.
As a technician, I remember a car that the tech working next to me was working on. He was an honest tech. It came in with an engine noise complaint. He was gently reving the engine in his stall to try to determine what the noise was. The engine scattered at about 2500 rpm.
So, running without proper lubrication is about like playing football on the freeway. You might get away with it, and you might not. Please don't do it on a freeway I'm driving on.