Revealing mistake: While Akeem is getting his hair cut, you can see the reflection of the white character he plays in the mirror. It is quite obviously a stand-in, with a fatter face and different glasses. (00:33:45)
Revealing mistake: When in the barber shop, the elderly Jew (played by Eddie Murphy) is shown in one shot. Then when the camera changes positions, he is shown again in the background. It is an obvious double, and doesn't look anything like Murphy did in the earlier shot.
Answer: How would Akeem's parents know what they were up to? They think he's taking an American vacation, and in the pre social media days, it was hard to keep track of people. As for McDowell, what sort of background check did you expect him to do on a fast food employee in the 80s? McDowell seems like a guy who would cut corners anyway.
Brian Katcher
There aren't exactly a lot of people lining up to work at McDowell's, so Cleo gives the applications a once over and hires them on the spot. I'm in my 40's and I've had plenty of jobs that didn't even call my references, let alone perform a background check.