If I remember correctly CO2 is heavier than O2 and will
settle out with the oxygen above it. Within reason will
the small quantities of CO2 created near the end of
fermentation protect the wine from oxidation?

I realize that the movement of a carboy or uncorking
in general will enter eddies in the air within the carboy,
allow some mixing of CO2 and O2 and also allow some
O2 to enter but would the CO2 quickly displace the oxygen
over the wine and protect it.

I not looking for guarantees here but an answer to something
like, if I open my carboy then replace the airlock would
giving the wine a quick swirl to release some dissolved
CO2 help to protect the wine from oxidation?

Don