We were puzzled when he carefully cut out the centre top disc of the capsule covering the cork, then he made the usual cut around the bottle neck, but not completely around. All became clear after the cork was extracted.
And then he fitted a drop-stop.
(the wine was good too at Neethlingshof Estate, Stellenbosch)
I believe that is the correct sommelier way to present someone with a bottle as you can inspect the cork as well rather than just hoping the cork was ok if the bottle was delivered to you without the cork.
A sommelier wouldn’t present a bottle without the cork in my experience.
They present the unopened bottle first, then remove the cork. In the USA they are punctilious about handing the cork to you and I see other diners sniffing or squeezing the cork. In the UK they tend to leave the cork on the table.
There’s little the cork can tell one; the crux is in the taste.
I’ve not seen presentation like above elsewhere. Of course, maybe it’s just that I don’t dine in the right places