I have done time in the OR and even then tubes were missed. Perfect environment for the procedures to be done. It's a relatively simple skill, but needs to be routinely practiced.
If a medic misses the tube in the field, people go all stupid about it. They start crying and saying such things as "omg why are you allowed to do these things?!". Yet when an MD misses the tube, it's just "wow, that must be a hard intubation.".
People really should pull their heads out of their butts and realize medics are well trained health care providers. They don't show you the laryngoscope and ETT in school and not teach you how to use them or have extensive practice in using them.
It's the people who think they know everything and say "I've done 1000s of these, I don't need to practice.", that give everyone else a bad rep.