Does pair programming ever turn into lengthy unproductive discussion?

Question

I was just thinking about pair programming and one thought just crossed my mind that surely at some time two coders are not going to agree and it would kind of turn into a lengthy (maybe heated) discussion about an implementation of a paradigm or algorithm, etc. I expect these might be 'religious' wars over stuff? Does this happen?

Having never 'pair programmed' ever, is this something that occurs? Are there processes to stop lengthy discussions?