"it is interesting to note that vulnerabilities in cross platform applications may transfer more easily to the Intel-based Macs running Mac OS X..."
You appear to have completely missed the phrase "Both x86 and PowerPC versions are provided." in the reproduction steps section. The problem is that, like many people these days, you see an apparent coincidence (that both use the same architecture, even though it's a false observation) and assume causality. If you write code with a buffer overflow and compile it for x86, PPC, ARM, MIPS and your toaster, the code will still have a buffer overflow on all of them.
What I'm saying is that the architecture doesn't magically make a bug appear in a system just because it is similar to another system. The vulnerability didn't "transfer" to OS X, it simply exists in the OS X version, just like it does in the other versions. Note that only the Mac and Windows version are confirmed, but it could just as easily exist in others.