Once we dissect friendship and make smaller sections of it - we can obviously identify some sections of friendship in which the answer to the question is a definite 'yes' - where a platonic relationship between a man & a woman exists. But, in my mind - these are just smaller sections of relationships - which should at best lie somewhere between acquaintance and friendship.
This small bit of wanting 'more' may at times be easy to suppress and lie about, it may even be thought of as insignificant and nothing more than a passing thought. The only point I am trying to make here is - if all 'just-friends' were to be honest, then in my view - at least one of the two (in all scenarios) will admit to have wanted more from the relationship, a.k.a friendship! If not, then I doubt if there was anything close to a real friendship to begin with.