Oops, sorry, edited my post so it doesn't make perfect sense.
Hello and welcome to the forum. I did some research on the internet and looks like it's normal for a Siamese/Egyptian Mau to have red pupils. Possible Houdini has some Siamese in him? I also came across someone with a creme colored cat who's pupils turn red. Since your kitty has been to the vet and there is no concern on your vets part, it appears to be normal. With the Siamese, it doesn't appear to *mean* anything, but just the way they are.