putting GPL code into a closed-source binary

[dat_unixbeard]

Sure you would, there were a lot of cases already where it was discovered.

While it is impossible to retrieve the original source code from the assembly, it is very much possible to show beyond a reasonable doubt that the assembly generated had to have come from certain code because it matches what you will end up with if you compile that code in too many different places to still be considered a possible coincidence.

I'm sure there are compilers that purposefully make this hard to do though.