I can give you the Tech's-eye view on this. The thing is, even as someone who has only just scratched the surface of medical understanding, I can see that lots of stuff becomes routine. I stand at the patient's head and hand swabs to the docs during pelvic exams; their part of the choreography is not a great deal more complex than mine. But little things can jump out and surprise you.
We had a guy who got drunk, slipped and fell on ice, and dislocated his shoulder. Based on his xray and his clinical presentation, the docs thought he might have a rare inferior dislocation. The staff doc couldn't quite remember the Latin term "luxatio erecta," so I found it on the Internet... and got to dazzle everybody with my newfound knowledge. 0.5% of dislocations are actually this type; cool! The doc did know quite a lot about how to manage these and what to look out for, even if the Latin name wasn't on the tip of his brain.
Then the drunk guy moved his arm, apparently with great effort and pain, though for no good reason, and he now had a boring anterior dislocation.
People are an endless source of amusement, wisdom, and general surprise for me, and the thing about EM is, we try to see a boatload of people each shift. So yeah, there is a lot of autopilot engaged. But as was said above, that just means you can direct your attention to the stuff that stands out.