But hey, you’re the expert…..!
rather a snarky reply but if most think it is oil in the exhaust then I'll just agree to disagree until someone can explain how a lot of oil gets there
and for only a short period before returning to 'normal' running..
I suggested the float gear and the nitrogen as a possible explanation without analysing the video frame by frame - it is also possible it was neither that nor the oil in the exhaust.