Yet other researchers did! Male and female.
The stats were eyewatering, not small margins in some cases. And many confounding factors were taken into consideration. It's impossible to include them all, you wouldn't be abe to make any comparisons at all!
I'd be very, very loath to dismiss the research because a male researching surgeon's professional opinion was bruised by them. He is welcome to add his voice to the debate, but not to dismiss, or be interpreted as dismissing, the research without very specific methodological reasons. And a wide spread of situations isn't necessarily an issue.
It's a new model of understanding. Currently based on 1.3 million patients who underwent one of 21 common elective surgeries in Ontario, Canada between 2007 and 2019. Not a small or quick study, by any means.
And the study itself makes no judgements, says the underlying reasons for the figures are not known, more study required. So again, one male researching surgeon should throw his weight behind further study rather than simply dismiss what could be something that could possibly be detrimental to 50+% of the world population.
As a researcher he should know better. Better than to make any simple statements, especially directly to the media!