It's an interesting study, but I note it took place in Ontario. Perhaps it should be repeated in other countries to eliminate any "local" differences.
I also see that in England, "women make up 41% of early stage surgeons but only 30% of higher trainees and 14% of consultants", so perhaps the riskier operations more likely to have a poor outcome will mainly be carried out by consultants (men). Any study would have to be careful to eliminate this potential bias.
Personally, I wouldn't care about the surgeon's sex, gender, sexuality, age, nationality, or race, but I would care about the surgeon's record for that particular type of operation and would hope that the data was available.