I used to work at an HPC research institute. While I agree with your sentiment most statistical software has bugs that effect results.

The panda's bug tracker stressed me out on a daily basis. I've also found bugs that effected results due to missing instructions between processor architectures, erasure coding in wire protocols for storage systems, and even a kernel bug.

But by far the most common was by the author of the model themselves.

Software has bugs, no exceptions.