Your bearing didn't spin from the fact you were using synthetic vs crude oil. Some other factor caused that failure. Could be improper installation, oil starvation either on fire up or during operation, bad tolerances, etc etc.

Tell you "expert" friend that there is a reason many new cars (including Corvette) roll of the assembly line with sythetic and that it is the recommended oil throughout the car's life. Even in the Marine industry, where I work, many engine manufacturers, like Volvo, have a sticker on the valve cover telling you to use synthetic.

One differerence between crude and synthetic is that batch after batch, sythetic is consistently the same. It is man made. Crude, being made from dead dynosaurs, can vary in composition batch to batch. That doesn't necessarily present a problem, but is just the way it is.

Like the guys said, use crude for the first 1500 to 2500 then if you want to, switch to synthetic.

Don