It is hard to detect subtle manipulation period. But assembly language is an extremely concrete representation of a program; it is not an especially great way to write underhanded code.
It's possible to write obfuscated assembly, of course, but it sticks out as obfuscated.
To further get your head around the lack of cover compiled code would give a backdoor, it's worth knowing that Hopper will give you serviceable C-ish code from x86_64 for... let me check here... fifty nine bucks.
(It's possible that my only message with that last graf is "Hopper is great").
assembly language is not an extremely concrete representation of a program if the hardware is engineered with backdoors which is exactly what this article suggests is happening.
if some specific set of registers is set a certain way followed by a very specific series of commands, there is no practical way to prove that the hardware is doing what it should.
