Normal dino oil has an odor hot we are used to. There is no reason I can think of that the synthetic may also have it's own distinct aroma.

The engine was never hot enough to burn the oil I would think. Even the oil going through the turbo bearings travels fast enough usually to avoid that.

You may have discovered a way to tell the type of oil in an unknown engine by noticing this. Or you have started a dip stick smelling contest.