Any two rotation matrices about a point should be distinct when acting on some arbitrary vector. That being said, two distinct rotations could certainly map some specific vector into another specific vector. That's what JeanMarie's answer addresses.
I think your issue, though, may have to do with the limitations of computational science: You don't have true rotation matrices. You're using MATLAB, right? Well, your matrices are stored as floating point arrays. That is, they suffer from limited computational precision. It wouldn't surprise me that two rotations that you might expect to be distinct don't compute that way.
I suspect the matrices in your question have been truncated after you copied and pasted them. If I attempt use the matrices as displayed in your question, I do see a difference:
Something you can look into is your machine and software limitations on floating point precision.