After having worked with some A&Ps (aircraft mechanics) I was shocked that surgeons didn't operate with checklists. Doesn't matter how skilled you are, mistakes happen, especially when you are in a hurry. Aircraft mechanics also typically 'shadow' their toolboxes, which is where every drawer has individual cutouts for each tool to make it easy to verify that all tools are back in their place. And apparently instruments being left in a patient isn't that uncommon:

"According to the U.S. Department of Health and Human Services, it is anywhere between 1 in 100 to 1 in 5000.[1] However a study done in 2008 reported to the Annals of Surgery that mistakes in tool and sponge counts happened in 12.5% of surgeries.[8]"

Why are aircraft mechanics taking better precautions against this type of low hanging fruit than surgeons, aside from ego?

Ref:https://en.wikipedia.org/wiki/Retained_surgical_instruments