Yes. True. Now Intel HAS to make the assumption that the silicon supports a feature the way the Intel CPU does if the feature bit is on.
It is not about the compiler but more about the hand optimized runtime libraries that are shipped with the compiler. The issue is more complex than the simple minded thinking "Intel cheated" and "AMD had to go to court for a fair deal".
Now, the Intel runtime library code checks the FEATURE bits and if set, assumes that the feature is properly supported on the silicon. If the bit is set, is an AMD CPU and it has a bug, there is no way to turn off the feature and no way to avoid running the program on the AMD CPU.
There are some subtle differences in the way AMD handles the AVX instructions. The GIMP math library built with GCC runs fine on Intel Sandy Bridge but fails intermittantly on the AMD Bulldozer parts when using AVX instructions. AMD users cannot correctly run the program and if the program was compiled with the Intel compiler could not check to see if it was on an AMD part.